Automated detection of problems in software application deployments

ABSTRACT

A system for monitoring and analyzing the operation of a deployment of a software application is disclosed. The system includes a monitoring component, a repository that stores a plurality of rules, and an analysis engine. The monitoring component collects data values of each of a plurality of state metrics associated with the deployment of the software application. At least some of the rules in the repository map respective combinations of states associated with the state metrics to corresponding problems. The analysis engine programmatically detects instances of said problems, at least in-part, by using the rules to analyze the state metric data values collected by the monitoring component. The rules can also include remedies associated with the detected problems, and the system may include remedy selection and execution modules.

CLAIM FOR PRIORITY

This application claims priority under 35 U.S.C. §119(e) to ProvisionalApplication No. 60/638,006, filed Dec. 21, 2004, the entire disclosureof which (including appendices) is incorporated by reference herein.

BACKGROUND

1. Field

This application relates generally to software management and morespecifically to systems and methods for programmatically monitoring andmanaging deployments of software applications.

2. Description of the Related Art

A variety of commercially available software tools exist for monitoringand providing information about software deployments. These productstypically (1) allow a user to statically specify certain aspects about aspecific software deployment, (2) monitor those aspects, and (3) alertthe user when the monitored aspects cross specified performancethresholds. These products do not provide any automated analysis ofmonitored data. They are best suited for simple automated monitoringtasks and then presentation of the monitored information in reports,which requires the user to manually analyze the reports to extractrelevant conclusions about the specific deployment. Examples of thesetypes of products include NetIQ's AppManager™ and Microsoft's MOM™.

The following well-known equation describes the availability (A) of asystem:

$A = \frac{1}{1 + \frac{MTTR}{MTTF}}$wherein MTTF is the Mean Time to Failure and MTTR is the Mean time toRepair. Based on this equation, the availability of the system isincreased by a decreasing MTTR and an increasing MTTF. Currentlyavailable tools provide monitoring capabilities that alert IT staff whenproblems occur. A single problem can result in multiple problematicevents. As a result, IT staff have to manually triage the problems topinpoint the root-cause problem that caused the set of problems. Thismanual triage increases MTTR. It also reduces the operational efficiencyof the IT staff, because they have to spend a significant portion oftheir time troubleshooting the problems. Also, currently available toolsare extremely limited in their ability to continuously optimize a systemor alert the IT staff to possible impending failures (for example due tothe possible exhaustion of resources), thereby resulting in a limitedMTTF. Therefore, currently available tools have a significant MTTR andlimited MTTF, resulting in a relatively low availability A.

SUMMARY

The present invention provides systems and methods for programmaticallymanaging deployments of software applications, including those indistributed environments. In particular, the present applicationdiscloses and describes various embodiments and inventive features of a“meta-application” that monitors and manages a deployment of anothersoftware application.

In a preferred embodiment, the meta-application creates and dynamicallyupdates an application model that includes data about the specificconfiguration of the deployed software application, the relationshipsbetween the various objects thereof, diagnostic troubleshootingprocedures for the represented objects, and other useful information.The application model can preferably be queried by the other componentsof the meta-application, to assist such other components in performingtheir respective functions.

The meta-application preferably includes a knowledge base comprisingencoded knowledge about the managed application, the knowledge beingstored in a format that the meta-application can use to detect theexistence of “problems” with the managed deployment. The encodedknowledge preferably maps known problems to logical combinations of“features” (as used herein, “features” may be anomalous or benignconditions) or other conditions associated with the managed deployment.The specific deployment conditions that map to a known problem can beweighted relative to each other, to reflect their relative importance.The knowledge base also preferably includes, for each problem, one ormore high-level remedies for curing the problem. The encoded knowledgemay include a variety of different types of knowledge, including,without limitation, knowledge base articles, diagnostic methods, bestpractices, and the like. Methods are also disclosed for automatedencoding of mass amounts of knowledge into a machine-readable formatthat can be used by the meta-application.

The meta-application gathers information, or “telemetry,” from themanaged application, and uses the telemetry to create mathematicalmodels that describe normal behavior of the managed deployment. Themodels are used to detect anomalous behavior (which may a type offeature) of the managed deployment, and also to predict possible futureproblems. The meta-application includes a number of problem detectionalgorithms, one of which (“Problem Logic”) efficiently maps logicalcombinations of conditions (e.g., features and deployment stateinformation) to known problems, the conditions comprising declarativeknowledge stored in the knowledge base. The meta-application canpreferably report problems that are either fully or partially “matched,”along with a confidence level associated with each matched problem. Theproblem-detection algorithms can advantageously leverage the deploymentinformation compiled in the application model.

When the meta-application determines the existence of problems, itpreferably ranks the problems by severity and determines an overallresolution strategy comprising high-level remedies. The meta-applicationcan report the problems and create low-level, deployment-specific plans(again, preferably by leveraging the deployment information in theapplication model) that can be manually executed by a humanadministrator or automatically executed by the meta-application. Asremedies and plans are executed, the meta-application preferably notestheir success or failure and, optionally, uses such information toadaptively refine the encoded knowledge.

If detected problems do not have associated remedies, or if the remediesfail to cure the problems, the meta-application can preferably conductroot cause analysis to determine an underlying source of the problems orto simply gain further insight. In a preferred approach, root causeanalysis involves correlating the problems to objects of the applicationmodel, using pattern recognition techniques to identify objects as rootcause candidates, and conducting diagnostic tests associated with theroot cause candidate objects.

For purposes of summarizing the disclosure and the advantages achievedover the prior art, certain objects and advantages of themeta-application have been described above and are further describedbelow. Of course, it is to be understood that not necessarily all suchobjects or advantages may be achieved in accordance with any particularembodiment of the meta-application. Thus, for example, those skilled inthe art will recognize that the meta-application may be embodied orcarried out in a manner that achieves or optimizes one advantage orgroup of advantages as taught herein without necessarily achieving otherobjects or advantages as may be taught or suggested herein. Further, itwill be recognized that the disclosed meta-application embodies a numberof distinct inventions, many of which may be implemented and practicedwithout others.

Accordingly, neither this summary nor the following detailed descriptionpurports to define the invention. The invention is defined only by theclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a meta-application that manages adeployed software application, in accordance with one embodiment of theinvention.

FIG. 2 is a schematic illustration of an embodiment of a system andmethod of allowing a plurality of deployment sites to leverage encodedknowledge, each deployment site having a meta-application and a managedapplication.

FIG. 3 is a schematic illustration of an embodiment in which ameta-application manages a deployment of Microsoft Exchange™.

FIG. 4 is a schematic representation of metadata tables for facilitatinga schema-neutral storage of information in an application model of oneembodiment of a meta-application.

FIG. 5 is a schematic representation of entity data tables for a singleentity, for facilitating a schema-neutral storage of information in theapplication model, in accordance with one embodiment of ameta-application.

FIG. 6 is a schematic representation of link tables that holdinformation about relationships between entities, for facilitating aschema-neutral storage of information in the application model, inaccordance with one embodiment of a meta-application.

FIG. 7 is a schematic representation of one embodiment of themeta-application, illustrating a particular deployment of monitors forgathering telemetry.

FIG. 8 is a schematic diagram illustrating how a meta-application'sanalysis subsystem analyzes telemetry, in accordance with one embodimentof the meta-application.

FIG. 9 is a graph of a state metric telemetry signal of a “poles” typeof signal category.

FIG. 10 is a graph of a state metric telemetry signal of a “flat” typeof signal category.

FIG. 11 is a graph of a state metric telemetry signal of an “integral”type of signal category.

FIG. 12A is a control chart of a telemetry signal of a state metric, inaccordance with one embodiment of the meta-application.

FIG. 12B is a graph showing an upper portion of a normalcy range of acontrol chart.

FIG. 12C is a feature confidence curve of a telemetry signal.

FIG. 13 is a trend chart of a telemetry signal of a state metric, inaccordance with one embodiment of the meta-application.

FIG. 14 is a discrete chart for a telemetry signal having discretevalues, in accordance with one embodiment of the meta-application.

FIG. 15 is a seasonality control chart for a telemetry signal of a statemetric, in accordance with one embodiment of the meta-application.

FIG. 16 is a Problem Logic circuit for evaluating a logic rule.

FIGS. 17-19 illustrate the construction and use of a discriminationnetwork for finding applicable portions of Problem Logic circuitry forevaluating a detected feature.

FIGS. 20 and 21 show sample screen shots of a graphical user interfaceof one embodiment of a meta-application.

FIGS. 22A-B show a knowledge base article for Microsoft Exchange™.

FIG. 23 is a diagram of application model objects and directed links,illustrating a root cause analysis method of investigating incriminatinglinks to find a root cause candidate object, in accordance with oneembodiment of the meta-application.

FIGS. 24 and 25 are diagrams of application model objects and directedlinks, illustrating root cause analysis methods of investigatingbystander objects to find a root cause candidate object, in accordancewith embodiments of the meta-application.

FIG. 26 is a diagram of application model objects and directeddependency links, illustrating a root cause analysis method ofinvestigating incriminating dependency links to find a root causecandidate object, in accordance with one embodiment of themeta-application.

FIG. 27 is a diagram of application model objects, illustrating a rootcause analysis method of finding differences between similar types ofobjects to find a root cause candidate object, in accordance with oneembodiment of the meta-application.

FIG. 28 shows an exemplary application model schema for one embodimentof a meta-application, which manages a deployment of MicrosoftExchange™.

FIGS. 29-40 show sub-topological application model schema for specificcomponents of the application model schema shown in FIG. 28,corresponding to servers, Active Directory, Exchange™ configuration,Windows™ services, IIS services, Exchange™ services, routing, storagegroups, public folder hierarchy, databases, third party software, andusers associated with the managed deployment.

FIG. 41 is a flowchart illustrating a diagnostic method fortroubleshooting a set of components of a deployment, in accordance withone embodiment.

FIG. 42 is an enlarged view of a portion of FIG. 41.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Overview

The present invention includes systems and methods for programmaticallymanaging deployments of software applications, including those indistributed environments. In preferred embodiments, the systems andmethods of the present invention are embodied in a “meta-application,”i.e., an application that at least partially automates the management ofone or more other applications. In various embodiments, these systemsand methods provide meaningful predictive analysis of deployed softwareapplications, enforce best practices on each deployment, detect theexistence of “features” and problem states of the deployment, executeremedial actions associated with the problem states, and/or perform rootcause analysis. Preferred embodiments of the meta-application providenumerous advantages, including, without limitation, increased deploymentuptime, decreased software management costs, reduced need for(potentially erroneous) human intervention, and automatic and continuousleverage of the latest public knowledge about the deployed application.

Systems and methods of the present invention are preferably designed toassist system administrators by at least partially automating the entirelifecycle of a managed application, including configuration,provisioning, maintenance, patching, problem diagnosis, healing, andday-to-day operations. By analyzing system behavior and selectingremedial and “best practice” actions to perform, the meta-applicationimproves and seeks to optimize application stability and performancewhile also optimizing system resources. Preferably, the meta-applicationis in charge of many of the system administrator activities associatedwith the managed application(s), including monitoring, updating,configuring, problem pinpointing, repairing, ongoing optimization, andprotecting. In particular, the meta-application is preferably configuredto quickly pinpoint the cause of a problem and then either automaticallyrepair it or direct manual repair via a human being. Either way, MTTR issignificantly reduced. In this context, the MTTR equals MTTI (mean timeto identify root cause of a problem) plus MTTH (mean time to heal theidentified problem). The meta-application advantageously significantlyreduces MTTI (which is usually the larger component of MTTR) and, inmany cases, MTTH. Moreover, the meta-application helps to eliminatehuman errors that often occur during deployment healing.

The various functions and methods described herein are preferablyembodied within software modules executed by one or more general-purposecomputers. These software modules, and the associated databases, may bestored on any appropriate type or types of computer storage device orcomputer-readable medium. In certain cases, some of the variousfunctions and methods described herein can be embodied within hardware,firmware, or a combination or sub-combination of software, hardware, andfirmware.

FIG. 1 illustrates a preferred embodiment of the invention, comprising ameta-application 20 that monitors and manages a deployment 10 (alsoreferred to herein as a “managed application”) of a software applicationhosted on one or more servers 12 over a computer network 5, such as alocal or wide area network. Each server 12 may include at least onemonitor 14 with one or more probes 16, and at least one component 18 ofthe managed application. It is also possible for monitors 14 to resideon the same server(s) as the meta-application 20, to facilitate“touchless” monitoring (see FIG. 7). The monitors 14 and probes 16assist the meta-application 20 in obtaining information from, executingactions upon, and executing application analysis in a distributedfashion on, the servers 12. Preferably, the monitors 14 and probes 16interact with the application components 18 by standardizedcommunication protocols, such as WBEM (Web Based Enterprise Management)elements 17. Also, monitors 14 and probes 16 can be deployed withinservers that do not include application components 18. For example, inembodiments in which the meta-application 20 manages a deployment ofMicrosoft Exchange™, monitors 14 may be deployed within Active Directoryand DNS servers. Further details of the configuration and operation ofthe monitors 14 and probes 16 are described below.

The meta-application 20 can be configured to monitor and manage a widevariety of different types of deployments 10. Examples of softwareapplications and hardware environments that the meta-application 20 canmonitor and manage include, without limitation, servers and storagesubsystems, databases such as Oracle Database 10g™ and MSSQL™, emailand/or messaging applications such as Microsoft Exchange™, applicationservers such as Weblogic™ and Websphere™, and web servers such asMicrosoft IIS™ and Apache™. The meta-application 20 is preferablyconfigured to monitor and beneficially manage any application (hardware,software, firmware, or a combination thereof) governed by the equationset forth in the Background of the Invention section of thisapplication.

The managed application 10 is preferably a software application orsystem that has interfaces or tools for gathering state metrics and forcontrolling system state. The managed application 10 may include anumber of sub-applications and services. In some cases, the deployment10 can be distributed across servers 12 that are located remotely fromone another. It will be appreciated that the meta-application 20 can belocated remotely from the deployment 10. It will also be appreciatedthat the meta-application 20 can be configured to monitor and managemore than one deployment 10. In one embodiment, the meta-application 20is configured to manage only one type of software application or system(e.g., only versions of Microsoft Exchange™). In an alternativeembodiment, the meta-application 20 can manage different types ofsoftware applications. The illustrated meta-application 20 comprises anorchestration module 21, a knowledge base 22, application model 24,telemetry database 26, plan database 28, user interface 29 (illustratedas a graphical user interface or “GUI”), analysis subsystem 30, andautomation subsystem 32, each of which is described below. Themeta-application 20 can reside on one or more servers.

The orchestration module 21 preferably runs a master algorithm over allother algorithms of the meta-application 20. All other algorithms arepreferably called as subroutines or run in independent threads managedby the orchestration algorithm. The orchestration module 21 ispreferably responsible for starting and stopping major activity threadsof the meta-application 20, such as Problem Logic (described below),when the meta-application as a whole starts and stops, and in between.

In a preferred embodiment, the orchestration module 21 establishes therelative priorities of all the major components of the meta-application20 and evaluates the performance of the system as a whole via anevaluation algorithm. The evaluation algorithm applies group rewards andpunishment to continuing tunable system parameter adjustments so as tooptimize system performance.

The orchestration module 21 preferably performs scheduling and initiatesoccasional maintenance, security, backup, and software rejuvenationactivities of the meta-application 20 and the managed applicationdeployment 10. The orchestration module 21 preferably also communicatesand cooperates with orchestration modules 21 of other cohortmeta-applications 20, if any, in a distributed network ofmeta-applications managing multiple application deployments 10.

The knowledge base 22 preferably comprises a repository of encodedknowledge about the deployed software application 10. Encoded knowledgecan comprise, without limitation, known problem states or “problems”associated with the deployed application 10. As used herein, a “problem”is a known problematic condition or behavior of an application orapplication deployment (portions of Provisional Application No.60/638,006, to which the present application claims priority, refer to“problems” as “symptoms”). The knowledge is preferably encoded in a formthat facilitates automated or computer-implemented analysis of thedeployment 10. The task of encoding knowledge can be performed by humanoperators (referred to as Knowledge Engineers or “encoders”), but it mayalso be partially or fully automated within software. Knowledge can beencoded from knowledge base articles of the type commonly used by ITpersonnel to manually resolve problems. For example, a particularknowledge base article may describe a problem that occurs when aparticular logical combination of conditions or states exist within adeployed software application, and may specify one or more possibleremedial actions for addressing this problem. The remedial actions maysimilarly be encoded in a format that enables the meta-application 20 toparameterize or configure a remedy for use within the particulardeployment 10 of the managed application, and to otherwise control theexecution of remedies. One example of a source of knowledge that can beencoded and stored in the knowledge base 22 is a Microsoft™ KnowledgeBase Article (see FIGS. 22A-B for an example of a MSKB article).Knowledge can also be encoded from other sources, such as documentederrors associated with the managed application 10, best practices thatspecify recommended configurations of the managed application 10,existing or customized diagnostic tools, and feedback data collectedover time from deployment sites (i.e., knowledge learned from thedeployments 10 themselves). The knowledge base 22 is preferablyconfigured to receive periodic updates as new knowledge becomesavailable (see FIG. 2). Knowledge can be encoded in any suitable format.In a preferred embodiment, knowledge is encoded in XML. Knowledge thatcan be used by the meta-application 20 may also comprise algorithms thatdynamically detect problems at runtime. Such algorithms can also bestored in the knowledge base 22.

In a preferred format, the knowledge is encoded as a plurality of logicrules that describe problems with the deployment 10 and/or deviationsfrom best practices. Logic rules are described further below. In apreferred embodiment, logic rules are statements that include logicalformulae and sub-formulae whose arguments comprise data describing thedeployment configuration and behavior. In the preferred embodiment, alogic rule can be thought of as a logical combination of conditions; ifeach condition is met, the rule itself is true. A logic rule can specifythe existence of a specific deployment configuration or behavior of thedeployment 10. Thus, logic rules may contain queries for informationfrom the deployment 10 or application model 24 (described below). Alogic rule can also specify the existence of “features,” which aredescribed below. The meta-application 20 interprets the truth of a logicrule as an indication of a problem or problematic symptom associatedwith the deployment 10. Note that “truth” can be considered in relativedegrees (i.e., logic rules can be less than 100% true), and themeta-application 20 can be configured to deal with relative degrees oftruth. Therefore, while the present disclosure refers in most instancesto the “truth” or falsity of rules, it should be understood that, inmany cases, it may be appropriate to consider the “relative truth” ofsuch rules. Thus, the meta-application 20 automatically detects problemswith the deployment 10 by analyzing the logic rules stored in the localknowledge base 22. As described below, when the meta-application 20confirms the truth of a logic rule, it can execute one or more remedialactions associated with the logic rule to attempt to cure the detectedproblem.

FIG. 2 illustrates a preferred system 50 and method of managing andupdating the content of local knowledge bases 22 of a plurality ofdifferent meta-applications 20 that monitor and manage a plurality ofapplications 10 in different deployment sites. In the illustratedembodiment, each deployment site includes a managed application 10, ameta-application 20, and a local knowledge base 22. In one embodiment,the various managed applications 10 are the same (e.g., all theapplications 10 are versions of Microsoft Exchange™). In anotherembodiment, the various managed applications 10 can be completelydifferent. Each managed application 10 may comprise a single softwareapplication or a set of software applications.

The method preferably involves the encoding 52 of knowledge about themanaged applications 10. As explained above, the knowledge to be encodedcan comprise known problems, remedies, best practices, and otherknowledge about the managed applications 10. The encoding can be donemanually, automatically, or a combination of both. Further details aboutpreferred encoding methods are described below. The encoded knowledge isstored in a central knowledge repository 54. Skilled artisans willappreciate that the central knowledge repository 54 can containknowledge about all of the different types of applications 10 that aremanaged by the group of meta-applications 20. Alternatively, there canbe a different central knowledge repository 54 for each different typeof managed application 10. In either case, any number of centralknowledge repositories 54 can be provided.

Preferably, one or more update servers 56 disseminate knowledge updatesor patches to various deployment sites of the managed application 10,via the Internet or another suitable communications network. Thedisseminated updates or patches may comprise, for example, updatedknowledge or changes to the local knowledge bases 22, new or updatedmonitors 14, revised algorithms, and the like. For example, when a newknowledge base article is published and encoded by a human encoder, anupdate may be sent to all of the deployment sites to add a newly createdlogic rule and associated remedies to each of the local knowledge bases22. The update servers 56 can be programmed to send new patches ofencoded knowledge to the local knowledge bases 22 according to variousdifferent criteria. For example, the update servers 56 can sendknowledge updates according to set periods (e.g., once a day, week,month, etc.) or based upon the amount of new and unsent knowledge storedin the central knowledge repository 54. The update servers 56 can alsosend knowledge updates based upon the importance of the unsentknowledge. For example, logic rules can be rated according to relativeimportance, so that the most important knowledge rules get sent first.In any case, it will be understood that it is ordinarily preferable tosend newly encoded knowledge to the local knowledge bases 22 as soon aspossible. In some embodiments, the update server 56 can instruct themeta-applications 20 to remove unneeded knowledge (e.g., older, nolonger relevant logic rules) from the knowledge bases 22, by sendingsoftware updates containing removal algorithms.

Although each deployment site shown in FIG. 2 has a locally installedmeta-application 20, it will be recognized (particularly in view ofFIG. 1) that the meta-application 20 need not run locally with respectto the managed application 10. In addition, there need not be aone-to-one correspondence between meta-applications 20 and managedapplications 10. Thus, for example, a single instance of themeta-application 20 could be operated as a hosted application thatmonitors multiple deployment sites from a remote location.

With reference again to FIG. 1, the application model 24 is preferably adistilled representation of the deployment 10, augmented with additionalinformation. When the meta-application 20 is first installed orconfigured for management of the deployment 10, the meta-applicationconducts a “discovery” process to populate the application model 24 withuseful information about the deployment 10. The meta-application 20preferably runs its discovery process periodically or continuously todynamically keep the application model 24 up to date. In a preferredembodiment, the application model 24 represents all of the objects ofthe deployment 10 (like software objects, servers, routers, storagesubsystems, etc.) and all of the physical and logical dependencies ofthese objects. For example, in an embodiment in which themeta-application 20 is configured to manage deployments of MicrosoftExchange™, the application model 24 might store the fact that anExchange™ server S1 has a Storage Group X, which contains a Database Y,which resides on SAN “foo” on Logical Disk D.

The application model 24 also preferably contains metadata for eachobject, such as data related to the “golden” or most preferredconfiguration for that object, as well as the object's currentconfiguration. The application model 24 also preferably containsinformation about what telemetry “metrics” are relevant to an object, aswell as parameterized troubleshooting procedures (“unit tests”), orreferences to such procedures (which can reside elsewhere), that can beused to measure the health of an object. The application model 24 canfurther include information about the relationships between variousobjects, as well as the normal flow of data and control signalstherebetween. Thus, the application model 24 is a “cached” view of thetopology of the deployment 10. Without the application model 24, themeta-application 20 would have to always obtain state/configurationinformation from the deployment 10, which can overburden the network andthe resources of the deployment environment. In a preferred embodiment,the application model 24 is kept in a database and only updated when thedeployment state or configuration changes. Note that the applicationmodel 24 can advantageously be used by algorithms contained within theproblem detector 38 to detect rules-based problems and problems found byconducting encoded diagnostic methodologies, as well as by the rootcause analysis module 41 to detect root-causes of problematicconditions. In preferred embodiments, most or all of the components ofthe meta-application 20 use the application model 24 to perform theirassociated functions.

As explained below, the application model 24 can be used by the analysissubsystem 30 and the automation subsystem 32 to dynamically obtainknowledge about the deployment 10, analyze the deployment 10 for theexistence of problems, create deployment-specific plans for remedialactions against the deployment, and perform root cause analysis. Theapplication model 24 gives the meta-application 20 the context oftenrequired for correct analysis. For example, if the meta-application 20wants to restart an important application service that has failed, theapplication model 24 can be used to locate the server of that serviceand to determine all the dependencies of that service, including whetherother important services are resident on that particular server. Ifthere are no other important services on the server, then themeta-application 20 can send a restart message to the service. If therestart message does not work, the meta-application 20 can restart theentire server. However, if there are other important services on thatserver, it may not be desirable to restart the server and disrupt thoseservices. Without this context provided by the application model 24, themeta-application 20 might mistakenly restart the server and causeadditional unwanted problems.

In a preferred embodiment, the analysis subsystem 30 is configured torequest and receive data from the deployment 10, analyze the receiveddata, detect “features” (described below) in the data, detect problemswith the deployment, select high-level remedies to execute against thedeployment, and/or perform root cause analysis (RCA). The illustratedanalysis subsystem 30 comprises a telemetry component 34, featuredetector 36, problem detector 38, remedy selector 40, and root causeanalysis (RCA) module 41.

The analysis subsystem 30 preferably includes a telemetry component 34that monitors and collects data values of various state metricsassociated with the managed deployment 10. The term “state metric,” asused herein, refers to a characteristic, condition, or state than can bemeasured or tested to generate a data value. State metrics can betime-variant metrics, such as CPU utilization, available disk space, andservice availability. A state metric data value refers to a data valueof a particular state metric; for example, CPU utilization=90%, orservice available=“unavailable.” The collected data is referred toherein as “telemetry” or “telemetry data.” The term “telemetry,” as usedherein, is not intended to imply that data is necessarily collected froma remote source. Rather, the source or sources of the telemetry data maybe local to the machine or machines on which the meta-application 20runs. A “telemetry stream” is a data signal for one state metric.

The telemetry component 34 preferably operates with the assistance ofthe monitors 14 and probes 16, which reside on the servers 12 of themanaged application deployment 10, on the same server(s) as themeta-application 20, or on other components. The monitors 14 and probes16 provide the infrastructure for the telemetry component 34 to requestand gather application state metrics (i.e., telemetry) from thedeployment 10. As explained below, the monitors 14 and probes 16 alsoprovide the infrastructure for the automation subsystem 32 to executeremedial actions against the deployment 10. The monitors 14 may also beused to distribute execution of analysis tasks that are thencommunicated back to the analysis subsystem 30. In a preferredembodiment, the monitors 14 and probes 16 comprise software components.However, hardware components or a combination of hardware and softwarecan be provided for cooperating with the telemetry component 34 andautomation subsystem 32 for the purposes described herein.

The meta-application 20 preferably stores collected telemetry data inthe telemetry database 26. The analysis subsystem 30 uses the storedtelemetry data to analyze past (often recent) behavior of the deployment10. In a preferred embodiment, the telemetry database 26 manages its ownstorage and automatically removes aged data. However, the management ofthe data within the telemetry database 26 could alternatively be done byother components, such as the telemetry component 34. In a preferredembodiment, since many telemetry analyses operate only on recenttelemetry data, the telemetry database 34 includes a caching mechanismto more quickly respond to those data queries. The meta-application 20preferably also stores features in the telemetry database 26. Like thetelemetry data itself, the features are also preferably automaticallyremoved as they age, albeit preferably at a slower rate than the rawtelemetry data. The telemetry database 26 can form a subcomponent of thetelemetry component 34.

After the above-described discovery process and the population of theapplication model 24, the meta-application 20 runs “best practice plans”that are customized for this deployment 10. Executing these plans servesto verify that there are no known configuration problems, and that thedeployment 10 is in a consistent state and is in conformity with bestpractices (e.g., the deployment 10 has downloaded and is running thelatest patches from the maker of the managed application).

The feature detector 36 continuously analyzes collected telemetry datato detect “features.” As used herein, a feature is a condition orbehavior of the managed application 10 that is known to be associatedwith a potential problem therewith. A feature can be benign, i.e., notin itself being unusual or anomalous. However, a feature oftenrepresents an unusual (but not necessarily problematic) condition orbehavior of the deployment 10. A feature might indicate the existence ofone or more problems, depending on whether other defined features exist.Examples of features are unusual spikes in CPU utilization, error logentries, loss of network connectivity, failure of a component orsubcomponent, storage exhaustion, unusual delays in networktransactions, abnormal performance of synthetic transactions, abnormalresource consumption, etc. The existence of a feature preferably causesthe problem detector 38 employ algorithms to (1) review the encodedknowledge for problems that are known to possibly cause the detectedfeature, and (2) possibly initiate more detailed telemetry gathering anddirect more extensive troubleshooting of a known problematic componentof the deployment 10. One way that the meta-application 20 detectsfeatures is to create “baselines” of various state metrics associatedwith the managed application 10. A baseline is a mathematical model thatdescribes the behavior of a state metric during “normal” operation ofthe managed application 10, wherein the meta-application 20 determineswhat is “normal” based on observation of the managed application for asuitable time period. The construction of baselines (also referred toherein as “baselining”) can be ongoing and dynamic, to continuallyreflect the current operation of the managed application 10. Forexample, a baseline can be a graph of the normal upper and lower boundsof a state metric as a function of time. If the monitored state metricdeviates to a prescribed extent from its baseline, the feature detector36 registers a new feature in the telemetry database 26. Baseliningmethods are described in further detail below. The meta-application 20preferably uses baselines in subsequent calculations for optimization,recovery, and root cause analysis. The feature detector 36 preferablydetects features by analyzing telemetry data stored in the telemetrydatabase 26 or telemetry data received directly from the telemetrycomponent 34.

The problem detector 38 preferably contains algorithms that request andprocess telemetry and features and identify deployment problems. Thesealgorithms preferably identify proper deployment 10 configuration,procedures to heal the deployment 10 when it has problems, procedures tooptimize the deployment when sub-optimal conditions are recognized, andprocedures to protect the deployment when it is compromised. Thesealgorithms may also orchestrate other peer algorithms in the problemdetector 38. One algorithm, “Problem Logic,” preferably analyzes thelogic rules stored in the knowledge base 22 to detect whether any rulesare currently “matched” or “true” (i.e., currently exist within thedeployment 10). As explained above, a logic rule can specify theexistence of specific deployment configuration parameters and statemetric values. Preferably, logic rules can also specify the existence ofone or more features. Thus, logic rules map logical combinations ofdeployment configuration parameters, state metric values, and/orfeatures to known problems associated with the managed application 10.In one embodiment, the problem detector 38 only analyzes logic rulesthat specify features discovered by the feature detector 36. In otherembodiments, the problem detector 38 systematically analyzes some or allof the logic rules in accordance with schedules that are eitherpreprogrammed or set by a system administrator of the managedapplication 10. The problem detector 38 can also be configured toautomatically select logic rules to evaluate based on currentlyidentified features and/or problems, thereby troubleshooting the rulesin an optimal way. Also, the feature detector 36 can itself beconfigured to independently detect problems by dynamically analyzing thedeployment 10 based on data gleaned from the application model 24. Inthis case, the feature detector 36 can employ algorithms that analyzethe deployment 10 without resort to the encoded logic rules. In someembodiments, the problem detector 38 is configured to use the RCA module41 to orchestrate the processing of logic rules, dynamically determiningthe best set of rules to analyze based on relevance, cost, and benefit.

In addition to storing logic rules for mapping deployment states toproblems, the knowledge base 22 preferably stores information aboutremedial actions, or “remedies,” that may be performed to eliminatespecific problems. Each remedy is stored in the local knowledge base 22in association with a particular problem. In some cases, a detectedproblem has more than one remedy, and the remedy selector 40 determinesthe preferred order in which to execute the remedies (i.e., if the firstremedy fails to correct the problem, then the second is executed; if thesecond remedy fails, then the third is executed; etc.).

Another form of knowledge that the meta-application 20 can use is a“plan,” which is an encoded administrative procedure. Each remedy canhave one or more plans that contain instructions on how to fix each typeof problem. In this context, a remedy can be thought of as a set ofplans and a policy for executing the plans. A plan is a specific orderof steps to address a problem in a specific fashion. The plans encodethe various actions that the meta-application 20 or the administratormay want to take against the deployment 10, including management actionslike “delete a user from the system,” troubleshooting actions like“restart a non-responding software component,” and remedy actionsassociated with knowledge base articles. The plans are preferably storedin an abstract format that encodes all of the specific actions requiredand the decision factors that allow the meta-application 20 to customizea plan to a specific deployment 10. In the illustrated embodiment, theplans are stored in the plan database 28.

In one embodiment, as problems are detected, they are reported by themeta-application 20 to associated IT personnel, together with associatedremedial actions and their plans that may be executed to address thedetected problem. Alternatively, the meta-application 20 may be designedor configured to automatically execute remedial actions associated withdetected problems. When a given remedial action is executed, themeta-application 20 preferably evaluates whether the associated problemstill persists, and logs the result.

In the illustrated embodiment, the automation subsystem 32 includes aplanning module 42 and an execution engine 44. The planning module 42preferably accepts high-level remedies and converts associated abstractor generalized plans into deployment-specific low-level actions. Theexecution engine 44 preferably executes those actions in a consistentand reversible manner against the deployment 10, and it preferablyallows such execution of such actions to be paused and resumed in aconsistent manner. The automation subsystem 32 can preferably alsoaccept high-level management tasks directly from a human administratorof the deployment 10, convert them into deployment-specific actions, andexecute them. In this manner the automation subsystem 32 leveragesencoded application knowledge (for example, a plan that encapsulates allthe steps required to restore a Microsoft Exchange™ server to a newmachine). Remedies and plans are described in further detail below.

In a preferred embodiment, the meta-application 20 is also adapted topredict future values of certain data streams associated with thedeployment 10. For example, the meta-application 20 can be adapted topredict the exhaustion of fixed resources (e.g., disk space), optimizeresource utilization (together with provisioning), and/or optimizeperformance.

As described below, the meta-application 20 may also implement a rootcause analysis (RCA) process for resolving less common, or coexistingproblems. Accordingly, the analysis subsystem 30 can include a rootcause analysis module 41 that implements the RCA process. The RCAprocess may be used where, for example, no logic rules exist for mappinga particular problem or set of problems to a corresponding cause orremedy. RCA may also be used in a fault-storm, which is a case wheremany problems are detected within a short period of time. In this case,the RCA module 41 would determine the most important faults to addressfirst.

Those skilled in the art will also recognize that the functionality ofthe meta-application 20 can be integrated with or “built into” theassociated managed application 10. Thus, the meta-application 20 and themanaged application 10 need not be provided as separate components.

Referring again to FIG. 2, each meta-application 20 can be configured toprovide feedback 58 that can be used in the knowledge encoding process52. The feedback 58 provided by a particular deployment site mayinclude, for example, some or all of the following information for eachproblem detection event: the problem detected, the associated logic rulethat triggered, the underlying features and/or telemetry data thatcaused the rule to trigger, the associated configuration state of themanaged application 10 at the time the rule triggered, the remedy orremedies executed in response to the problem detection event, and theoutcome of each remedy execution event. This information may be usedover time by human personnel and/or automated rules generation andanalysis software to adaptively refine the logic rules and remediesstored in the local knowledge bases 22.

In an exemplary embodiment, illustrated in FIG. 3, the meta-application20 is adapted to manage a deployment 10 of Microsoft Exchange™. Thedeployment 10 is provided on one or more servers 12, as explained above.The meta-application 20 preferably runs on a dedicated server 60, andmonitors and manages the Exchange Servers 12 and Active Directoryservers 62 over a local area network (LAN) or wide area network (WAN).The meta-application 20 can also monitor other related components, likea DNS server, SMTP, etc. Skilled artisans will appreciate that thenumber of servers 12 can be relatively large (e.g., ten to twentyservers 12). While a meta-application 20 can be employed to manage awide variety of different types of applications 10, specific examples ofa meta-application are described herein in the context of managingMicrosoft Exchange™. However, it should be understood that the conceptsdescribed herein are not limited to any specific type of application 10.

Consider again the above-mentioned equation describing a system'savailability:

$A = \frac{1}{1 + \frac{MTTR}{MTTF}}$It will be appreciated that the meta-application 20 advantageouslyincreases the availability A of the deployment 10. The meta-application20 seeks to reduce MTTR by providing quick insights to the systemadministrator on the root causes of problems and providing plans toquickly repair the deployment 10. In addition, by continually optimizingthe running deployment 10, enforcing best practices, and analyzing theavailable resources, the meta-application 20 reduces unexpectedfailures, thereby increasing MTTF. A reduction in MTTR coupled with anincrease in MTTF increases the overall availability A of the deployment10.Application Model

Application Model Information

The application model 24 (FIG. 1) includes detailed knowledge about theapplication 10 that is managed by the meta-application 20. Theapplication model 24 comprises metadata describing the static anddynamic aspects of the environment being managed. In a preferredembodiment, the application model 24 comprises the information listedbelow. Skilled artisans will appreciate that the application model 24can consist of more or less than what is listed below.

-   -   1) A list of all objects (physical and logical) that define the        domain of the managed application 10, the objects' key        attributes (e.g., what is the critical state of the object), and        the objects' behavior (e.g., actionable things that the object        can do). This includes the application 10, various other        subcomponents, infrastructure objects (including networking,        storage, and security objects), and the current and historical        configuration information of each of these objects.    -   2) A set of inter- and intra-object dependencies, including the        order in which objects (e.g., services) are launched, the order        in which various dynamic runtime libraries (or DLL's) are loaded        by each of the objects, etc. Also preferably included is the set        of valid commands that can be sent to these objects. Any command        that is not valid is preferably prevented from being executed.    -   3) The relationships between the objects and metadata about        those relationships, including telemetry “metrics” that can be        used to determine the health of the relationship. The        meta-application 20 is preferably initially provided with a        predefined “abstract” application model that includes all        possible allowed configurations and topologies. Once discovery        is completed, the meta-application 20 uses this information to        validate and instantiate the actual topology and configuration        of the deployment 10. Each relationship can have three types of        metadata: arity, directionality, and type. The arity describes        the number of objects of a specific type at each end of the        relationship. Possible arities are 1-to-1, 1-to-n, n-to-1, and        n-to-n. The directionality determines which object type is the        “from” side of the relation and which object type is the “to”        side of the relation. The “type” of the relationship determines        the semantic meaning of the relationship. There are at least        five types of relationships: dependency, delegation,        containment, policy propagation, and event. For example, in a        well designed Exchange™ server there is a one-to-n dependency        relationship to an Active Directory from an Exchange™ server.        With this a priori defined rule, the discovery module is aware        that there will be at least one active directory and one or more        Exchange™ servers. If this rule is violated, the event is logged        for future analysis and reporting as a violation of best        practices to the administrator.    -   4) Constraints on the values for properties of each type of        object. These constraints represent “sanity checks” on the        values detected during discovery. For example, a server IP        address must be four positive integers between 0 and 255        separated by periods.    -   5) Flow of data and control signals between objects in the        application model 24. Data flow is the path taken by the data        payload between objects. For example, if the managed application        is Exchange™, these two objects might be an Outlook™ client and        the Exchange™ server. Control flow describes the “signaling”        that controls the flow of data. For example, a request to DNS        (Domain Name Service) for name resolution is a control flow.    -   6) For preferably each object, all telemetry metrics that can be        used by various algorithms, including RCA algorithms, to map        problems to the object, even when there is a feature detected        but no rule is associated with the feature.    -   7) Troubleshooting procedures associated with an object, which        can be used by various algorithms, including RCA algorithms, to        determine the current health of a object.

The information defined above can be captured in the application model24, which can be represented as an object graph. Define G and G* asfollows: G is the abstract graph that describes the complete environmentto be managed by the meta-application 20 (it is preferably provided withthe uninstalled version of the meta-application), while G* is computedthrough discovery and populated with actual information. All keycomponents of the meta-application 20 (e.g., monitoring, analysis,automation) can preferably use the application model 24.

FIG. 28 shows an exemplary application model schema, or object graph,for a meta-application 20 that manages a deployment 10 of MicrosoftExchange™. FIG. 28 shows, at a high level, the topology of thedeployment 10. The various boxes represent objects of the deployment 10,and the arrows represent links therebetween. The links between the boxescan also be considered as objects of the application model 24. Apreferred application model 24 stores various metadata, described above,with these objects, including the links. Unit tests can be stored inconnection with the illustrated boxes and links.

One of the boxes shown in FIG. 28 is a box 280 representing serversassociated with the deployment 10. FIG. 29 shows an object graph for theservers. In other words, FIG. 29 shows all of the instances of serversof the deployment 10, represented as a sub-topology of the applicationmodel schema shown in FIG. 28. Similarly, FIGS. 30-40 showsub-topological object graphs for Active Directory, Exchange™configuration, Windows™ services, IIS services, Exchange™ services,routing, storage groups, public folder hierarchy, databases, third partysoftware, and users associated with the application model represented inFIG. 28. Those of ordinary skill in the art will appreciate that theillustrated application model schema represent an application model foronly one particular deployment 10, and that an application model schemawill vary depending upon the type of software application that themeta-application 20 manages, as well as on the specific configuration ofthe particular deployment 10. Skilled artisans will also understand fromthe teachings herein that FIGS. 28-40 only illustrate a topology andsub-topologies, and that a preferred application model 24 includes muchmore information (including metadata about objects, links betweenobjects, data flows between objects, dependences, etc.) than what isshown in these figures.

When the meta-application 20 is initially installed, it auto-discoversmost or all of the components of the deployment 10 using the abstractapplication model (G). A description of this set of components is thensent to the application model 24, which builds a completecontext-sensitive model of the deployment (G*). The meta-application 20uses information from the application model 24 (if the deployment 10 isExchange™, such information may comprise, e.g., the number of mailboxes,number of servers, network organization of servers, available bandwidth,etc.) to choose a set of monitors 14 to deploy and a set of statemetrics to be observed. Then “empirical baselines” for each of thesestate metrics are chosen. The empirical baselines contain things likethe initial set of state metrics important for this deployment, initialvalues for key system parameters such as CPU utilization, volume oftraffic, disk utilization and schedules for maintenance tasksappropriate for this deployment. These empirical baselines arepreferably provided with the uninstalled version of the meta-application20 as part of the abstract application model G. They can be computed byanalyses of reference material of the type of software application beingmanaged (e.g., books, websites, knowledge base articles, consultants,etc.) and empirical analyses done on a wide variety of differentdeployments 10 of the managed application.

Once an empirical baseline is chosen, the meta-application 20 can beginanalyzing the deployment 10. The meta-application 20 initially runs“best practice plans” as described above. Then the meta-application 20computes the initial set of telemetry metrics and deploys the minimumnumber of monitors 14 required to gather them. Finally, themeta-application 20 begins its analysis of the deployment 10 bygathering telemetry from the deployment. Its first task is to create adeployment-specific baseline (discussed below) for each telemetry metricthat it is tracking, to augment the empirical baseline initially chosenafter the meta-application 20 was installed.

In one embodiment, the application model 24 is stored in a standard SQLdatabase. This allows the application model 24 to “answer” queries orquestions about the configuration of the managed application 10 forother components of the meta-application 20. Historical configurationinformation (i.e., a record of the configuration specifics over time) isalso preferably stored in the application model 24 to allowadministrators to view the entire history of the deployment 10 and howit has changed over time.

A querying language interface can be provided to allow the applicationmodel 24 to answer queries received by the analysis subsystem 30 (e.g.,by the problem detector 38, RCA module 41, remedy selector 40, or othersubcomponents thereof) and/or the automation subsystem 32 (e.g., theplanning module 42, the execution engine 44, or other subcomponentsthereof). The querying language interface preferably also allows thesequeries to be indexed and cached to improve querying performance.

Schema-Neutral Data Storage

The application model 24 preferably allows schema-less storage of itsinformation for seamless upgrading of an installation of themeta-application 20. When a software application like themeta-application 20 is upgraded, very often the schema (the way in whichits data is organized on disk) will change. In a preferred embodiment,the meta-application 20 can upgrade itself and maintain its historicaldata about the managed application 10 for extended periods of timewithout restarting. A schema-neutral data store module is preferablyprovided, which can accept multiple schemas and query across all ofthem. This allows data stored in older schemas to still be accessedafter a newer version of the meta-application 20 begins using a newschema to store the same type of information.

To accomplish this, the meta-application 20 preferably maintainsmetadata tables for each type of data, which store the locations of theactual data. The metadata tables keep track of the other tables (e.g.,SQL tables or HDF5 groups) that hold the actual information. Exemplarymetadata tables maintained by the meta-application 20 are illustrated inFIG. 4 and described below. Skilled artisans will appreciate that othertypes of tables and table content can be provided and maintained, whilestill providing schema-neutral storage.

A discovery table 64 records when discovery (the process responsible forgathering that information stored in the application model 24) wasconducted. It is used to track which rows in the data tables werediscovered at different times. Thus, the discovery table preferablyholds all of the known discovery events. In one embodiment, thediscovery table has the following columns:

-   -   “did”—an integer “discovery ID” column. Each “did” represents a        different run of the discovery process.    -   discovery_time—the time the corresponding discovery process        started.

A schema table 66 records all the different versions of the schema thathave been installed by the meta-application 20. In one embodiment, theschema table 66 has the following columns:

-   -   schema_id—a character sequence of the form “yymmdd_v”, which        represents the installation date and sequence number of the        schema. For example, if two different versions of a schema were        installed on Aug. 13, 2004, the schema table would have two rows        with a schema_id of ‘040813_(—)1’ and ‘040813_(—)2’.    -   initialized_by—the login name of the person who installed this        schema version.    -   xml_definition—a large object column which contains the entire        XML schema.    -   xml_checksum—the checksum of the xml_definition column. This is        used by the database code to determine if the schema that a user        specifies has already been installed.

An entity map table 68 records the names of the actual tables that holdthe data for a given entity. For example, for SQL entities, this tablecontains the names of all the tables that hold data for different schemaversions of an entity. Also, for HDF5 entities, the entity map table 68holds the names of HDF5 files and the names of the groups. In oneembodiment, the entity map table 68 has the following columns:

-   -   schema_id—the schema identifier.    -   entity_name—the name of the entity.    -   table_name—for SQL, the name of the table that holds the data        for this version of the entity.    -   history_table_name—for SQL, the table that holds the historic        data for this version of the entity.    -   commit_table_name—for SQL, the table that holds the commit        information for this version of the entity.    -   hdf_group—for HDF5, the name of the HDF5 file and group that        contains the data for this entity.        Two records in the entity map for the same entity can have the        same table_name and history_table_name values if the underlying        definition of the entity is the same in both versions of the        schema.

An attribute map table 70 records the names of the actual columns thathold the data for different schema versions of a given attribute. In oneembodiment, the attribute map table 70 has the following columns:

-   -   schema_id—the schema identifier.    -   entity_name—the name of the attribute's entity.    -   attribute_name—the name of the attribute.    -   attribute_type—the “type” of the attribute (e.g., a string).    -   column_name—for SQL or HDF5, the name of the attribute's column.    -   sql_column_type—for SQL, the database type of the attribute        (e.g. NVARCHAR).    -   hdf_column_type—for HDF5, the HDF type of the attribute (e.g.        String).    -   vector_entity_name—only for “Vector” attributes: the name of the        entity that holds the actual set of values for the vector.        In the illustrated embodiment, two records in the attribute map        for the same attribute can have the same column_name values if        the underlying definition of the attribute is the same in both        versions of the schema.

A link map table 72 records the names of the actual tables that hold thelinks between two specific entities. The link map table 72 contains thenames of all the SQL tables or HDF5 files and groups that hold data fordifferent schema versions of a link. In one embodiment, the link maptable 72 has the following columns:

-   -   schema_id—the schema identifier.    -   from_entity—the name of the “from” entity in this relationship.    -   to_entity—the name of the “to” entity in this relationship.    -   link_type—the type of relationship represented by this link.    -   table_name—for SQL, the name of the table that holds the link        along with its historic data.    -   commit_table_name—for SQL, the name of the table that holds the        commit data for this version of the link.    -   hdf_group—for HDF5, the name of the HDF5 file and group that        holds information on the link.        Two records in the link map for a given pair of entities can        have the same table_name values if the definition of the link is        the same in both versions of the schema.

Entity data tables preferably hold the actual information for theentities. FIG. 5 shows features of the entity data tables for a singleentity, according to one embodiment. In the illustrated embodiment, fora given version of the schema, each entity has associated with it acurrent entity value table 74, a historic entity value table 76, and anentity commit table 78. The current entity value table 74 holds the mostrecent information for the entity and preferably has one column perattribute. The historic entity value table 76 holds all historic values(i.e., a record of previous values) as well as all temporary uncommittedupdates. Rows are preferably added to the table 76 each time updatesoccur to the entity table. The entity commit table 78 holds an “updatesequence number” and a “commit time” for each update.

In a preferred embodiment, it is expected that the following data accesspatterns will be the most typical: Most queries will perform simple“selects” and “joins” using the current value tables 74. Historicqueries will include scans of the historic value table 76. Updates willpreferably be achieved via stored procedure calls that insert a recordinto the commit table 78 followed by several inserts into the historicvalue table 76, in turn followed by updates into the current value table74 and ending with an update of the record in the commit table 78.

The name of the current entity value table 74 can have any of a widevariety of forms, such as “entity-name_D schema-id” (e.g.“HOST_D040812_(—)1”). As mentioned above, the table 74 preferablyrecords the current information for an entity. In one embodiment, thetable 74 has the following columns:

-   -   oid—the object ID which uniquely identifies the entity in this        table. It can optionally be implemented as a simple IDENTITY        column that starts with 0 and is incremented by 1 with each new        record.    -   usn—the update sequence number, which represents the last        committed update that was applied to this record.    -   did—the discovery ID. This is an integer column which can be        used to identify different discovery runs.    -   additional columns to hold the most recent attribute values for        this entity.

The name of the historic entity value table 76 can have any of a widevariety of forms, such as “entity-name_H schema-id” (e.g.“HOST_H040812_(—)1”). As mentioned above, the table 76 records thehistoric information for an entity and preferably has the followingcolumns:

-   -   oid—the object ID which identifies the corresponding entity in        the current value table 74.    -   attr_name—the name of the attribute that corresponds to the        attribute value.    -   usn—the update sequence number corresponding to the attribute        value.    -   attr_value—the value of the attribute.    -   applied—a boolean flag used during the update process to        indicate whether the update represented by this record has been        applied to the corresponding record in the current value table        74.

The name of the entity commit table 78 can have any of a wide variety offorms, such as “entity-name_C schema-id” (e.g. “HOST_C040812_(—)1”). Asmentioned above, the table 78 records the commit status of the updatesto the entities and preferably has the following columns:

-   -   usn—the update sequence number representing the specific update        action.    -   commit_time—the time at which the update was committed.

FIG. 6 shows two tables that preferably hold the actual informationabout related entities. In one embodiment, for a given version of theschema, each link has associated with it a link table 80 and a linkcommit table 82. The link table 80 preferably holds recent and historicinformation for the links, as well as details of a specified type ofrelationship between two entities. The link commit table 82 preferablyholds an update sequence number and a commit time for each update to itscorresponding link table 80.

The name of the link table 80 can have any of a wide variety of forms,such as “entity1-name_entity2-name_type_L schema-id” (e.g.“DOMAIN_HOST_PC_L040812_(—)1”). As mentioned above, the link table 80preferably records the current and historic information for all linksbetween two entities. In one embodiment, the link table 80 has thefollowing columns:

from_oid—the object ID which identifies the “from” entity

to_oid—the object ID which identifies the “to” entity

did—the “discovery ID” of the discovery run which identified this link.

insert_usn—the update sequence number of the update that added thislink.

delete_usn—the update sequence number of the update that deleted thislink.

The name of the link commit table 82 can have any of a wide variety offorms, such as “entity1-name_entity2-name_type_C schema-id” (e.g.“DOMAIN_HOST_PC_C040812_(—)1”). As mentioned above, the link committable 82 records the commit status of the updates to the links. In oneembodiment, the table 82 has the following columns:

usn—the update sequence number representing the specific update action.

commit_time—the time at which the update was committed.

Thus, skilled artisans will understand from the teachings herein, andparticularly FIGS. 4-6, how to maintain multiple versions of theapplication model 24 across numerous updates and upgrades of themeta-application 20, without difficult or problematic data migrations.For further guidance, U.S. Provisional Patent Application No. 60/638,006discloses, in Appendix C, an example application model schema usedwithin a meta-application 20 for managing Microsoft Exchange™.

In a preferred embodiment, the meta-application 20 includesfunctionality for performing efficient querying of static queries. Themeta-application 20 preferably knows beforehand the forms of allpossible data queries that the data store is able to perform, but notalways the specific data to be queried. Specifically, themeta-application 20 preferably knows what tables will be queried andwhich columns will be used for query constraints and joins. In thisembodiment, the meta-application 20 may sometimes know exactly whatvalues will constrain a query, but generally it will not. Since the datain the data store can change, it may not be useful to cache the resultsof a known query. However, it is useful to cache the data structuresused to perform the query, which allows for quicker responses toqueries.

Thus, the meta-application 20 preferably includes a persistence systemthat caches and maintains a known set of queries that themeta-application 20 might execute as well as usage frequency informationfor each query. In a preferred implementation, queries that arecompletely bound are stored in a first cache (closest to returning theresult). These bound queries already know exactly what table (e.g., SQLtable) and constraints to use. A second cache contains queries that arenot completely bound, such as a query that might lookup a server with aname to be provided when the query is executed. These unbound queriescan be though of as prepared statements.

The persistence system of the meta-application 20 preferably alsomaintains a cache of frequently accessed data in memory, organized forfast lookup and good locality of reference, for the queries that aremost frequently executed. So if a specific query looks in table foo forcolumn bar with a specific value, rows in table foo will be split intotwo cached tables, one for column bar and one for the other columns.

Gathering Telemetry

Monitors and Probes

As explained above, with reference again to FIG. 1, the meta-application20 uses monitors 14 and probes 16 to collect telemetry data (alsoreferred to herein as “state metrics” or “telemetry metrics”) from thedeployment 10 of the managed application. In the illustrated embodiment,a monitor 14 encapsulates all the different ways that themeta-application 20 can gather telemetry data from, and control, thedeployment 10. Each probe 16 preferably runs inside of a monitor 14 andis responsible for gathering data for a specific telemetry metric. Theanalysis subsystem 30 is preferably concerned with gathered telemetrymetrics, and leaves the details of how to gather them to the monitors14. The automation subsystem 32 preferably just worries about“operators” and lets the monitors 14 deal with how to execute them onthe deployment 10. In a preferred embodiment, a monitor 14 is a piece ofcode, such as executable program or DLL (dynamic link library) file. Theapplication model 24 can maintain a mapping of all possible telemetrymetrics associated with each application model component/object. Thisallows algorithms to dynamically create problem identificationprocedures at runtime without the need for pre-built rules.

Monitors 14 can preferably use both local and remote APIs (applicationprogram interfaces) to access the managed application 10. Thissimplifies installation of the meta-application 20, because it is notnecessary to modify any deployment 10 components in order for themeta-application to monitor them. In addition, certain components, likerouters and firewalls, can typically only be managed via remote APIs.Microsoft Windows™ has the ability to monitor and remotely control mostdeployment 10 components via remote APIs. Thus, remote monitors 14 canprovide a significant amount of the functionality required to manage thedeployment 10.

Monitors 14 can reside locally with respect to the deployment 10, orlocally with respect to the meta-application 20. In a preferredembodiment, one monitor 14 is provided on each server 12 of thedeployment 10. In this case, the monitor 14 can preferably use all theremote and/or local APIs (some application-specific APIs are onlyaccessible locally on the server 12 on which the application isinstalled). In addition, local monitors 14 can minimize the bandwidththey use by sending only “diffs” of telemetry data (differences betweentwo data sets). Local monitors 14 can preferably also operate whennetwork connectivity to the meta-application 20 server (themeta-application 20 is preferably provided on one server, but could beprovided on a plurality of servers) is lost. In such a case, a localmonitor 14 can preferably batch collected data and send it whenconnectivity is regained. Local monitors 14 preferably also have theability for local analysis of telemetry, as well as identification offeatures or problems and associated resolutions, thus providing adistributed analysis capability to the meta-application 20. For example,if the monitor 14 senses that the deployment 10 is about to crash, themonitor can gracefully and immediately shut down services to minimizedata loss.

The meta-application 20 preferably analyzes and chooses (e.g., when itis first installed) the set of telemetry required to manage, theapplication deployment 10. Monitors 14 can be categorized by theapplication component they monitor and control. For example, there maybe an Exchange™ Server monitor, a Microsoft DNS Server monitor, a CiscoPIX Firewall™ monitor, etc. The meta-application's knowledge base 22preferably has a mapping of telemetry metrics to monitors 14. Monitors14 can register themselves with the telemetry component 34 (discussedbelow), which then configures each monitor 14 with respect to the typeand frequency of telemetry required.

FIG. 7 shows a meta-application 20 that manages two differentapplication platforms 84 and 86. The meta-application 20 comprises acontroller 88 and an administrative user interface 29 (illustrated as agraphical user interface or GUI). The controller 88 may be implementedon one or more different servers and includes the analysis subsystem 30and automation subsystem 32 discussed above. Also shown are monitors 92and 94. As shown, the monitors can reside either locally with respect tothe managed application (such as the monitor 92) or within thecontroller 88 (such as the monitor 94). The monitor 92 resides locallywithin the application platform 84, and sends telemetry to the analysissubsystem 30, possibly using SOAP (Simple Object Access Protocol). Theautomation subsystem 32 can send deployment healing commands to themonitor 92 for healing the application platform 84. The monitor 94resides within the controller 88, and gathers telemetry from applicationplatform 86 via any of a variety of protocols, such as SNMP (SimpleNetwork Management Protocol), RPC (Remote Procedure Call), and the like.The automation subsystem 32 can send healing commands to the monitor 94,which remotely executes them against the application platform 86.

Referring again to FIG. 1, in a preferred embodiment, each monitor 14 isimplemented as a “container” process with the ability to load new probes16 at runtime (on Windows™ platforms, monitors 14 can preferably loadnew probes 16 as DLL files during runtime using the LoadLibrary™mechanism). In this context, the probes 16 can be thought of as newtelemetry capabilities. Monitors 14 send telemetry to themeta-application 20 in chunks of data called “telemetry packets.” Thetelemetry component 34 can preferably configure the container process tocontrol the frequency with which it sends telemetry packets and the typeof telemetry metrics in each packet. The container process is preferablyalso configurable with respect to the protocol it uses to send thetelemetry packets. Each packet can be tagged with a “priority” that themeta-application 20 can use to determine the packet's importance. Themonitor 14 can use platform APIs to gather all requested metrics, form apacket, and then send the packet using the negotiated protocol.

FIG. 8 illustrates preferred methodology or process flow of the analysissubsystem 30, as it pertains to Problem Logic (discussed below). Asshown, the telemetry sent by the monitors 14 is received by thetelemetry component 34, which processes the telemetry (discussed below).The meta-application 20 can be configured to send urgent telemetry(e.g., telemetry that clearly or probably comprises evidence of aproblem with the deployment 10) directly to the problem detector 38,while the rest of the telemetry is stored in the telemetry database 26.The feature detector 36 analyzes the received telemetry to detectfeatures, which are passed on to the problem detector 38. The featuredetector 36 may use feature detection algorithms 25 (discussed below) todetect the features. The problem detector 38 uses the knowledge from theknowledge base 22 to detect problems associated with the detectedfeatures. The remedy selector 40 then analyzes the detected problems toidentify appropriate remedies and develop a healing strategy.Information associated with the detected problems and remedies are thensent to the automation subsystem 32. The telemetry component 34, featuredetector 36, problem detector 38, and remedy selector 40 canadvantageously use information received from the application model 24 toperform their associated tasks.

Thus, the analysis subsystem 30 is where the meta-application 20 doesits telemetry analysis and problem identification. The illustratedmeta-application 20 uses a staged approach to telemetry analysis withanalyses getting increasingly complex as the data proceeds to the nextstage. The analysis subsystem 30 is preferably heavily multithreaded tomaximize responsiveness. Also, because much of the analyses are notsynchronized and their execution run at different rates, thearchitecture preferably allows related tasks to have disparate executiontimes while still being able to cooperate with each other. Each threadpool preferably has synchronization data structures that reduce thecomplexity of global thread management.

Telemetry gathering may require quasi-realtime processing constraints,so that the meta-application 20 can avoid dropping telemetry oroverflowing network buffers. To enforce this, all telemetry-processingtasks are preferably given a priority and are executed in priorityorder. If tasks need to be dropped, then preferably only the lowestpriority tasks are eliminated. To facilitate timely response to incomingtelemetry, the entire telemetry-processing loop is advantageouslymultithreaded. The most time-sensitive task is performed by thetelemetry component 34, which preferably monitors all of the incomingtelemetry and prevents overflow of network buffers. A telemetry priorityqueue (TPQ) can be provided to decouple the telemetry component 34 fromthe rest of the analysis subsystem 30, so that the component 34 can feedtelemetry packets to the TPQ without regard for how quickly theprocessor thread is taking telemetry tasks off of the TPQ. The threadpool of the telemetry component 34 preferably accepts telemetry frommonitors 14 and then labels each packet with a priority. The telemetrypacket is then inserted into the TPQ that is sorted by telemetrypriority. In addition to the TPQ, a scheduled priority queue (SPQ) canmaintain “scheduled” tasks sorted by task priority. The SPQ prioritiesare preferably in the same “units” as the TPQ priorities to facilitatecomparison against each other. The meta-application 20 preferablyinserts tasks into the SPQ when it needs to execute an internal task,such as responding to updates from the update server 56 (FIG. 2) orregular configuration synchronization with the application model 24. Thepriority of a scheduled task is zero when it is not time for execution,and increases over time after it passes its scheduled time of execution.Tasks also may change in priority as other algorithms measure and recordtheir utility. The highest task in both queues is compared and thehigher priority task is chosen.

The chosen task is then assigned to a thread from the thread pool of thetelemetry component 34. Packets are first split into their constituentparts. Each telemetry part is then processed according to its type. Eachtelemetry type has a predetermined sequence of tasks that are invokedfrom the processor thread. These tasks include things like insertioninto the telemetry database 26 and feature detection.

Meters, Redundancy Avoidance, and Postprocessors

In embodiments of the invention, the managed application 10 is providedin a distributed environment, and the meta-application 20 may reside onone or more servers that are physically remote from the managedapplication. In this arrangement, the points of measurementspecification of telemetry (e.g., the one or more servers on which themeta-application 20 resides) and actual collection (e.g., the servers 12containing components of the managed application 10) are different. In apreferred embodiment, the meta-application 20 specifies “what” is to bemeasured by gathering up all relevant information required to effect themeasurement, conglomerating it into some structure or record (referredto herein as a “meter”), and transmitting that information to a point ofdata collection. The infrastructure at the data collection point (in theillustrated embodiment, one or more monitors 14) uses the meter'scontents to effect the measurement, and then packages that informationinto one or more discrete packets (i.e., state metrics) for shipmentback to a point of processing, storage, and/or aggregation, typicallynear the place where the meter was originally created. In oneembodiment, the telemetry component 34 is the point of meter creationand processing.

The task of gathering up all relevant information to effect measurementcan be burdensome, especially in systems where many different codepoints in numerous contexts might want to gather data. In preferredembodiments of the present invention, this task is simplified byproviding an application model 24, which is a well-structured databaserepresenting a distilled view of the environment where things aremeasured. The application model 24 advantageously provides a means ofextracting metadata relevant for telemetry measurement. In other words,the application model 24 helps to reduce the amount of “work” that themeta-application 20 needs to do in order to gather information about thedeployment 10. In these embodiments, it is more convenient to place theburden of gathering information on the meter itself.

In a preferred embodiment, the general method of data collection is asfollows. The measurement “client” (e.g., the monitor 14) specifies anentity or set of entities on which the measurement should be performed,the type of measurement that should be performed on the given entities,and any parameters (not determinable by context) required for themeasurement. The measurement “server,” specifically the meter or pieceof infrastructure that creates the meter (e.g., the meta-applicationcontroller 88 of FIG. 7), then ensures that the set of specifiedentities makes sense for the kind of measurement requested, extracts allinformation relevant for measurement from the application model 24, andpackages that information, along with parameters (raw or processed),into itself. The code that acts as a measurement client (e.g., themonitor 14) becomes much simpler as a result, and the metering systembecomes much more flexible, maintainable, and extensible.

In some systems, it is possible and likely that many disparate elementsof the system's components within the same process will requestidentical (or nearly identical) sets of telemetry data in themeter-based approach described above (typically as the result ofbrute-force application of rule-based demands for data). Disparateelements of a system's components in different processes on the same oron different originating computers may also ask for the same meter-baseddata. It is difficult to coordinate on the distributed demand-side(i.e., at the monitors 14) to ensure that only one instance of the meteris running at any given time. Those elements demanding metrics fromtheir identical meters may start and stop their measurements at anytime, with no coordination between them. The network costs oftransmitting the duplicate copies of a given meter to the point of datacollection (e.g., monitor 14) is low compared to the overall cost oftransmitting the resulting metrics back to the point of meter creation.It is therefore not too costly to allow these redundant copies of metersto run to the data collection point. It is very costly, however, toeffect separate measurement of the same data source for each copy of themeter, to arrive at what is essentially the same set of metrics.

Therefore, the monitors 14 are preferably configured to preventredundant measurement of data in distributed systems. Each monitor 14preferably recognizes redundancies in the different metering requestsarriving at a data collection point, and effects only a single stream ofmeasurements to derive all the metric values to be sent back to thoseelements in the analysis subsystem 30 requesting the measurements. Themetric set can be sent back to each originating host/process separatelyand “demultiplexed” there to advise each separate requester (typicallythe meter creators) of the metrics' values.

There are efficient ways to determine whether multiple meters arrivingat the data collection points represent the same essential request.These methods are much more efficient than brute-force comparison of allmeter internal data. For purposes of comparison, there are some elementsof the packaged meter that might be deemed immaterial for comparison(e.g., frequency of measurement under certain restricted conditions).

In a preferred embodiment, filters or aggregators (collectively referredto herein as “postprocessors”) are applied to collected telemetry datato lessen the network burden of sending collection metrics from the datacollection point (e.g., monitors 14) to the data consumer (e.g.,analysis subsystem 30). A set of postprocessors could be constructed ascomponents separate from the meters, with each postprocessor beingwidely applicable to a number of different kinds of meters. Effectivepostprocessing then is a matter of creating the appropriate meter, andthen attaching the appropriate postprocessor to the meter. As the metergenerates metric values (state metrics), those metrics make their way tothe postprocessor, which then applies appropriate filtering,aggregation, and/or transformation to those input metrics to generate aseparate stream of output metrics. The number, nature, and content ofthe output metrics need not correspond tightly to the input metrics. Thepostprocessor usually changes the nature of the output data, sometimesdrastically. The meter/postprocessor coupling sends back to the dataconsumer only the output metrics from the postprocessor.

A variety of different types of postprocessors are possible. Forexample, one type of postprocessor is an IDENTITY postprocessor, whichdoes not change the meter output in any way. In this case, the couplingof the meter and postprocessor generates results identical to what wouldhave been generated by the meter alone. Another type of postprocessor isone that filters data according to some static or dynamic criteria,allowing input metrics through as output metrics without modification ifthey match the filtering criteria, and completely eliminating the inputmetrics otherwise. Yet another type of postprocessor is one that appliessome formulaic transformation. For example, such a postprocessor candouble the value of each metric, or apply a “lookup” table function tometric values. Skilled artisans will appreciate that other types ofpostprocessors may be desirable and useful. A postprocessor can also bea composite of several other types of postprocessors.

Postprocessors may also be useful in ways other than limiting networktraffic. For example, in some embodiments, postprocessors make the dataconsumers in the analysis subsystem 30 much easier to construct becausesome of the data processing burden occurs at the point of datacollection (e.g., the monitors 14), thus simplifying the content of thetelemetry stream.

Just as the measurement infrastructure (in the illustrated embodiment,the monitors 14) can avoid duplicating measurements and generation ofredundant metrics at the point of data collection, similar concepts canbe applied to postprocessing. For two different meter/postprocessorcouplings with the same meter but different postprocessors, the same rawmeasurement (the data-source-facing action) can be applied, butdifferent postprocessors can be applied to the metrics stream togenerate two separate sets of metrics, as desired by the metricsconsumers (in the illustrated embodiment, elements of the analysissubsystem 30). Two different data consumers can, of course, specify thesame (to a sufficient degree) meter/postprocessing coupling, in whichcase the whole pipeline at the point of data measurement is shared forboth (for the data-sink-facing action).

There are several main concepts relevant to a preferred total avoidanceof redundant measurement. A meter preferably has a “source-facing hash”that combines elements relevant to the meta-application controller 88(e.g., machine name, telemetry name, etc.). The source-facing hash isderived from the meter's “significant and source-relevant attributes.”Similarly, a meter/postprocessor coupling preferably has a “sink-facinghash” that combines elements relevant to the monitoring APIs of a server12 of the deployment 10 (e.g., which APIs are being used, whichcomponents are being monitored, how many hooks are in this server,etc.). The sink-facing hash is derived from the coupling's “significantand sink-relevant attributes,” the sink-relevant attributes being asuperset of the source-relevant attributes. It is also possible thatinformation present on the meter and/or the postprocessor can be“advisory” or “suggested” and not count as relevant attributes forpurposes of this discrimination. The system uses the source-facinghashes and sink-facing hashes to eliminate redundant meter gathering andredundant post processing, respectively.

Redundancy can also be avoided in transmitting all metrics streams backto data consumers in the analysis subsystem 30. Preferably, the monitor14 transmits only one copy of the data back to the single process(and/or host) that may host multiple data consumers for identicalmeter/postprocessor couplings. The data-consuming side can worry aboutnotifying all consumers of newly arrived metrics data (demultiplexing).

There is often more than one way to collect any given piece of data, soa given meter's set of metrics could be collected from one of severaldifferent sources in a distributed environment of a deployment 10. Themeta-application 20 is preferably configured to leverage existing datacollection infrastructure of the deployment 10, if any exists. In oneembodiment, the monitors 14 are configured to collect metrics throughdifferent native APIs on a given platform (e.g., Win32, Linux kernelinterface, etc.). Metrics can also be collected through a low-levelmeasurement service provider (e.g., WMI on Windows™), or through otherproducts that collect and aggregate such information.

The meta-application 20 can also be configured to employ differentmethods for measuring the same data according to various criteria. Forexample, the meta-application 20 can measure telemetry data based onglobal system-determined or user-specified preferences for differentmeasurement methods. Alternatively, measurement preferences can bespecified on a per-meter basis. For example, a CPU measurement mighttake fewer resources on a server 12 of the deployment 10 than pagefaults per second. As another example of per-meter measurementpreferences, it might not make sense to measure disk usage more thanonce a minute. The meta-application 20 can also collect telemetry databased on the current availability of measurement resources. Also, somedata collection API's may not be reliable, in which case the monitor 14should retry using another API. Skilled artisans will understand thatother data measurement preferences can be provided at the same or othergranularities. Specific policies for how to measure and cache specifictelemetry metrics can be stored in these preferences.

In such a system, one would usually prioritize measurement methods foreach meter based on preferences. Some measurement methods could beabsolutely prohibited, perhaps based on dynamic criteria. Themeta-application 20 can be configured to keep track of which allowablemeasurement methods are currently available, as well as those that donot work. Also, the meta-application 20 can be configured to dynamically“arbitrate” the measurement of a given meter between differentmeasurement points and measurement methods, based on currentavailability and preference. In one embodiment, the meta-application 20always attempts to measure the meter by selecting a currently availablemethod having the highest priority, and switching the method based onvarying availability, preference, and prohibitions.

Feature Detection

Feature Detection Overview

With reference to FIGS. 1 and 8, this section describes algorithms 25and structures used by the analysis subsystem 30 to identify featuresfrom raw telemetry data, create “baselines” for gathered telemetrysignals, and create normalcy bands for the telemetry signals. In theillustrated embodiment, these activities are performed by the featuredetector 36. The following describes preferred embodiments of thefeature detection algorithms, structures, and methodology of themeta-application 20. Skilled artisans will appreciate that manyvariations of these are possible.

The meta-application 20 preferably includes telemetry analysisalgorithms 25 (FIG. 8) that identify suspicious or anomalous trends orstates from raw telemetry. Streams of telemetry are analyzed differentlydepending upon the type of telemetry. Numeric telemetry is analyzedusing statistical techniques, and when a telemetry value of a particularstream does not match a statistical profile for the stream, a feature isgenerated. Other types of telemetry are analyzed using pattern-matchingtechniques. All feature-detection algorithms finish by adding detectedfeatures to a “feature list,” which allows different algorithms tosynchronize themselves. The feature list is preferably stored in thetelemetry database 26.

Each feature preferably has an associated lifetime that themeta-application 20 uses to determine when it is appropriate to removethe feature from the feature list. Removal allows the meta-application20 to prevent false positives and to clean out features that have notaffected application performance or stability. Note that if a featuredid have such an effect, it would have triggered a problem (describedbelow), and the meta-application 20 would have changed the feature'slifetime value. Further, if the meta-application 20 resolves thedetected problem, then the feature itself should disappear.

Modeling Deployment Behavior

Specific analysis algorithms and heuristics used by the meta-application20 to model the behavior of the deployment 10 and to convert rawtelemetry into “predicates” that are used to detect and representspecific conditions, such as “slow CPU” or “almost full disk,” will nowbe described.

The meta-application 20 utilizes telemetry streams from a managedapplication 10 to determine the health of said application, possiblyusing metadata about appropriate telemetry for each applicationcomponent from application model 24. The algorithms 25 are preferablyconfigured to detect whether a specific stream of telemetry shows theexistence of specific anomalous states in the deployment 10 or acomponent thereof, such as an unusually slow CPU, a hard disk that isalmost full, message queues that are growing at a high rate, or emaildelivery that is slow. The feature detector 36 preferably uses thealgorithms to mathematically analyze the raw numerical telemetry todetermine if certain anomalous conditions are met. This sectiondescribes some of the techniques used to analyze non-cyclical andnon-linear telemetry signals.

A preferred method uses a “classification algorithm,” a “modelingalgorithm,” and “control charts.” The classification algorithmrecognizes telemetry signals or streams as belonging to one of aplurality of signal categories, each category describing the generaltype of signal. For example, in one embodiment the classificationalgorithm uses signal categories entitled “constant,” “flat,”“integral,” “polynomial,” “noise,” “poles,” or “times” (or alternativetitles) defined as described below. A different set of predefined signalcategories may alternatively be used. The modeling algorithm, which canbe recursive with respect to itself and the classification algorithm,computes numerical parameters of a mathematical model of a telemetrysignal (e.g. mean and standard deviation of a normal distributionmodeling white noise.) The mathematical models are used for “baselining”and feature detection.

The classification algorithm dynamically analyzes a stream of numericaldata to mathematically determine the signal category to which itbelongs. The signal categories describe fundamentally different types ofsignals. A constant stream contains the same numerical value repeatedforever (e.g., 5, 5, 5, 5, 5, 5, . . . ). A pole stream tends to havetwo classes of values. The majority of the pole signal values are in onenumerical range (e.g., zero), and a minority of the pole signal valuesare in another numerical range. FIG. 9 shows an example of a polessignal. A flat stream tends to contain runs of the same numerical value(e.g., 5, 5, 5, 5, 5, 5, 5, 5, 7, 7, 7, 7, 7, 7, . . . ). FIG. 10 showsan example of a flat signal. An integral stream either constantlyincreases or decreases in value. FIG. 11 shows an example of an integralsignal. A polynomial stream can be modeled by one specific polynomialfunction (e.g., x²+2x+2=0). A noise stream contains random values thatare not easily described by a mathematical equation (e.g., thedifferences between the nth and n+1 th values tend to be large and thederivatives are also noisy). A times stream is the product of two otherstreams, as in the expression Stream₁*(1+Stream₂).

The meta-application 20 preferably identifies each of these signalcategories by its specific mathematical properties. Accordingly, themeta-application 20 conducts a test for each category, where each testmay be generated as a result of processing knowledge stored in theknowledge base 22 or generated dynamically by a higher-level featuredetector. As each telemetry feed is monitored, it is classified into oneof these categories by conducting each category's test. The integral,poles, and times categories are compound or recursive, meaning that theybuild upon another category, such as polynomial. So a feed might becategorized as a “times” feed combining polynomial and noise streams.

The modeling algorithm then uses these signal category classificationsto generate a description of each feed. Each mathematical category hasits own specific set of statistical measures to describe the values inthe feed. The constant category only has the value of the numbers in thefeed. The flat category models both the various values of the feed andthe size of the changes in the feed when they occur. So the flatcategory model is recursive and is composed of a model representing thevarious y values of the feed and another model representing the size ofthe non-zero changes in y. The integral category model records whetherthe feed is increasing or decreasing and the recursive modelrepresenting the first derivative of the stream. The polynomial modelrecords the equation that describes the telemetry stream. The noisemodel is represented by either a Gaussian or Gamma distribution. Thepoles model contains a recursive model representing the height of the“spikes” or “poles” of this telemetry feed. The times model records thetwo recursive models used to represent this telemetry feed. These valuesare computed and can be used to detect abnormal conditions that areregistered in the telemetry database 26 as features. These mathematicalmodels can be updated periodically (either manually or by themeta-application 20) or dynamically (by the meta-application), basedupon new telemetry streams and/or modifications of the formulae forcomputing numerical parameters of the mathematical models. Suchmodifications may be based upon, for example, knowledge learned byanalyzing the historical use of the deployed software application 10,feedback received from persons that use or control the deployed softwareapplication 10, and/or new publicly available knowledge of the softwareapplication 10. For each component of the model (poles, flats, etc.), atype of “control chart” (described below) can be created to profile thatportion of the telemetry signal.

The classification or assignment of a telemetry signal to a signalcategory can be accomplished dynamically by the meta-application 20based upon an analysis of a received telemetry signal. Alternatively,the classification or assignment of a telemetry signal to a signalcategory can be done prior to monitoring the telemetry signal, basedupon knowledge of the particular metric being monitored. For example, itmay be known beforehand that, in a given deployment of the softwareapplication being managed, a particular metric is always constant (the“constant” signal category) or always oscillating for short periodsbetween different values (“flats”). In such cases, the meta-application20 can be configured to assign this telemetry signal to the known signalcategory without executing the classification algorithm for thisparticular metric.

Numerical Charts

The analysis subsystem 30 is preferably configured to generate numericalcharts for analyzing real-time telemetry streams, for the purpose ofdetecting features that can be entered into the meta-application'sProblem Logic circuitry (described below). In a preferred embodiment,there are three types of numerical charts: control charts, trend charts,and seasonality charts.

FIG. 12A shows an example of a control chart 95 for a given telemetrymetric. The control chart 95 shows a telemetry signal 94. A normalcyrange of the telemetry signal 94 is characterized by an upper threshold91 and a lower threshold 93. The upper threshold 91 is characterized byan upper zero-confidence level T₀ (feature confidence equals 0), anupper trigger-confidence level Tc (feature confidence equals c), and anupper full-confidence level T₁ (feature confidence equals 1), which aredescribed below. Similarly, the lower threshold 93 is characterized by alower zero-confidence level T₀ (feature confidence equals 0), a lowertrigger-confidence level T_(c) (feature confidence equals c), and alower full-confidence level T₁ (feature confidence equals 1). Skilledartisans will appreciate from the teachings herein that control chartscan have several different forms, depending upon the telemetry signal.In the illustrated chart 95, the telemetry signal 94 reaches points 106,which can be considered as anomalous behavior of the measured metric andcan be registered as features in the telemetry database 26.

When the real-time telemetry signal 94 crosses above the upper threshold91 or below the lower threshold 93 (and more preferably thetrigger-confidence levels T_(c) thereof), the feature detector 36preferably generates a corresponding feature. Fine-grained control canbe provided by specifying a preprocessing smoothing average window, arequired “sustain time” for a deviation, and a trigger confidence level.Thresholds of numerical charts can measure a telemetry signal absolutelyor statistically.

To further illustrate the theory and approach behind numerical charts,consider FIG. 12B, which shows a graph 180 that represents an upperthreshold of a normalcy range of a control chart. In this graph 180, they-axis is the value of a specific telemetry metric, and the x-axis istime. The graph shows a telemetry stream 182 of a state metric, withconfidence levels T₀ (confidence equals 0), T_(c) (confidence equals c),and T₁ (confidence equals 0) superimposed thereon. The confidence levelsT₀, T_(c), and T₁, which respectively indicate feature confidence valuesof 0, c, and 1, can be computed based on mathematical models, describedabove. These confidence values are feature predicate confidence values(see Confidence subsection of Detection of Problem States sectionbelow). A plurality of points 190 on the telemetry stream 182 representdetected features associated with the particular state metric beingmonitored.

Thus, in a numerical chart, a monitored metric's normalcy rangepreferably has a low threshold and a high threshold (either threshold isoptional). A threshold is an interval [T₁,T₀] or [T₀,T₁]. The featuredetector 36 (FIG. 1) preferably initiates feature generation at the“trigger” confidence level T_(c), and preferably continues generatingfeatures until the confidence returns to 0. Feature confidence can rampup linearly within [T₀,T₁] (i.e., confidence is 0 at T₀, c at T_(c), and1 at T₁). The problem detector 38 can preferably accept a profusion offeatures generated with different confidence values. Since the triggerconfidence is c, the first feature generated by a numerical chart willhave a confidence greater than or equal to c. In the control chart 95 ofFIG. 12A, the signal 94 crosses above the upper trigger-confidence levelT_(c) and subsequently remains above the upper zero-confidence level T₀for the chart's sustain period, resulting in the generation of a feature97. The signal 94 then crosses below the lower trigger-confidence levelT_(c) and subsequently remains below the lower zero-confidence level T₀for the sustain period, resulting in the generation of a feature 99. Theconfidence of a feature reported from a chart is preferably the featurepredicate confidence that is eventually seen by Problem Logic (discussedbelow). Numerical charts and Problem logic preferably share the samedefinition of “confidence.”

FIG. 12C shows a “confidence curve” 192 mapped to the telemetry value.The confidence curve 192 is a piecewise linear function clamped tointerval [0,1]. Superimposed on the confidence curve 192 are verticaldotted lines 194, 196, 198, 200, 202, and 204. The dotted lines 200,202, and 204 respectively represent a zero-confidence level, atrigger-confidence level, and a full-confidence level associated with anupper threshold of the telemetry signal. In one embodiment, the featuredetector 36 generates new features with corresponding confidence valuesaccording to the following methodology, it being understood that othermethods are also possible. When the monitored state metric has a valuebetween the lines 198 and 200, the confidence value is zero, andtherefore the feature detector 36 preferably does not generate any newfeatures. When the monitored metric increases above the line 200 but isbelow the line 202, the confidence of a feature is between 0 and c, andthe feature detector 36 can be configured to (but preferably does not)generate new features with such confidence values. When the monitoredmetric increases above the line 202, the confidence of a new feature isnow c, and the feature detector 36 preferably begins generating newfeatures with appropriate confidence values until the telemetry signaldecreases below an arbitrary value, such as the line 200 that representszero confidence. A similar methodology can apply with respect to thedotted lines 194, 196, and 198.

In a preferred embodiment, the variables used by numerical charts arethe following: Tau (τ) is a parameter that determines the weights thatare applied in the calculation of mu (μ) and sigma (σ). Use τ=∞ tocompute ordinary mean and sigma, and use 0<τ<∞ to emphasize recenthistory as done in an EWMA chart which uses an exponentially weightedmoving average. Mu (μ) is the mean of the data added to the chart. Sigma(σ) is the standard deviation of the data added to the chart. “ForgetSamples” (N_(F)) is the maximum number of samples retained in the memoryof the chart. When this limit is reached, adding a new point will pushout the oldest point. “Forget Time” (T_(F)) is the maximum time that asample is retained in the memory of the chart. When the time coordinatex of a point is too old compared to the time coordinate x of the mostrecent point, then the old point is purged.

“Low” refers to a chart's low threshold, which is specified by a triple[true,L₁,L₀] or [false,L_(c),c]. In the first form, L₁ is theconfidence=1 level, L₀ is the confidence=0 level, and confidence rampsdown linearly on threshold [L₁,L₀]. The width of the threshold isΔL=L₀-L₁. In the second form, L_(c) is a calibration level withconfidence=c. The width of the interval, ΔL=3 σ, is determined fromsignal history. Limits L₀ and L₁ can be calculated from L_(c), c, andΔL, wherein L₀=L_(c)+c ΔL, and L₁=L_(c)−(1−c) ΔL. The threshold is[L₁,L₀].

“High” refers to a chart's high threshold, which is specified by atriple [true,H₁,H₀] or [false,H_(c),c]. In the first form, H₁ is theconfidence=1 level, H₀ is the confidence=0 level, and confidence rampsup linearly on threshold [H₀,H₁]. The width of the threshold isΔH=H₁-H₀. In the second form, H_(c) is a calibration level withconfidence=c. The width of the interval, ΔH=3 σ, is determined fromsignal history. Limits H₀ and H₁ can be calculated from H_(c), c, andΔH, wherein H₀=H_(c)−c ΔH, and H₁=H_(c)+(1−c) ΔH. The threshold is[H₀,H₁].

“Trigger Confidence” (t) is the confidence level at which featuregeneration is initiated. The high trigger level H_(t) is calculated asH_(t)=H₀+t ΔH=(1−t) H₀+tH₁=H_(c)+(t−c) ΔH. The low trigger level L_(t)is calculated as L_(t)=L₀−t ΔL=(1−t) L₀+t L₁=L_(c)−(t−c) ΔL. “AverageSamples” (N_(A)) is the maximum number of points that will be consideredin smoothing average preprocessing of the input signal. “Average Time”(T_(A)) is the maximum time that will be considered in smoothing averagepreprocessing of the input signal. “Sustain Samples” (N_(S)) is theminimum number of points required to sustain a positive confidencedeviation before a feature is generated. “Sustain Time” (T_(S)) is theminimum time required to sustain a positive confidence deviation beforea feature is generated.

In a given control chart, points (x_(i), y_(i)) are progressively addedto the chart by an incoming signal. The x-coordinate is time and they-coordinate is some measured telemetry metric. Preferably, a limitednumber N_(F) of points are remembered, and points are remembered onlyfor a limited duration of time T_(F), where passage of time is indicatedby the most recent point added to the chart. The mean (μ) and standarddeviation (σ) of the data are preferably determined by exponentiallyweighted moving averages (EWMA):

$\mu = \frac{\sum\limits_{{({x_{i},y_{i}})} \in C}{{\mathbb{e}}^{{- x_{i}}/\tau}y_{i}}}{\sum\limits_{{({x_{i},y_{i}})} \in C}{\mathbb{e}}^{{- x_{i}}/\tau}}$$\sigma^{2} = \frac{\sum\limits_{{({x_{i},y_{i}})} \in C}{{\mathbb{e}}^{{- x_{i}}/\tau}( {y_{i} - \mu} )}^{2}}{\sum\limits_{{({x_{i},y_{i}})} \in C}{\mathbb{e}}^{{- x_{i}}/\tau}}$

The tau (τ) parameter determines the weights applied in the calculationof mu (μ) and sigma (σ). In order to weight them evenly, it is preferredto use τ=∞. In order to emphasize recent telemetry history, it ispreferred to use 0<τ<∞. A z-statistic can be defined as follows:

$z = \frac{y_{i} - \mu}{\sigma}$The z value can be reported when a feature is detected and registered.

Detecting Trends

In a preferred embodiment, the meta-application 20 is also configured toprofile application performance trends and, in appropriatecircumstances, detect anomalous or problematic trends in certaintelemetry signals. It is noteworthy that sources of knowledge (such asMicrosoft™ Knowledge Base Articles) sometimes specify the existence oftrends as conditions precedent for the recognition of problems. Inpreferred embodiments, the meta-application 20 provides “trend charts”that can be used to detect rising trends and/or descending trends. Whena trend is detected, a feature is preferably generated and registered inthe telemetry database 26.

FIG. 13 shows a trend chart 106 for a monitored metric. The chart 106includes two different bands. The top band shows an incoming telemetrysignal 108 for the monitored metric. The lower band shows a waveform110, which is the incoming signal 108 processed to detect “risingtrends” and “descending trends.” The processed signal 110 is fed into acontrol chart 112, which is similar to the chart 95 shown in FIG. 12A.Accordingly, the upper and lower thresholds of the control chart 112 areeach characterized by a zero-confidence level T₀ corresponding tofeature confidence of zero, a trigger-confidence level T_(c)corresponding to feature confidence of c, and a full-confidence level T₁corresponding to feature confidence of 1. The signal processinggenerates a positive or negative pulse when a rising or descending trendis detected. The squares 113 are features.

A trend can occur when the input telemetry signal is strictly monotonicfor a sufficient number of samples and time. Trends occur when thederivative (slope) of the smoothed input telemetry signal is uniformlypositive or negative for a sufficient number of samples and time (thesustain samples N_(S) and sustain time T_(S)). The trend chart detectstrends near their beginning points (the portions of the signal at whichthe trends begin) by effectively passing the derivative of smoothedinput signals into a control chart.

Seasonality

Many times, cyclic behavior can be observed in the performance ofdeployments 10 of infrastructure applications due to the patterns ofhuman users. For example, for a deployment 10 of Microsoft Exchange™,every morning at 9 am mail servers might generally experience heavy loadbecause everyone checks their email when they arrive at work. In anothercase, a large batch of emails may be sent at the end of each quarter toannounce results to investors and shareholders of a financial company.In addition, managed applications 10 can have internally scheduledactivities, such as daily backups, that can impact performance.

In these instances, the meta-application 20 is preferably configured toprofile cyclic application behavior, so that it recognizes these cyclicsurges in use and does not report heavy load as a performance problem.In a preferred embodiment, the analysis subsystem 30 (preferably thefeature detector 36) analyzes metrics' telemetry signals for each of aplurality of relevant time cycles (e.g., day, week, month, and year). Adata set for each telemetry feed is preferably built, where thedimension representing time is normalized by computing the modulo of thetime cycle. For example, Monday at 3 pm can be normalized to 3 pm on day2 (assuming Sunday is day 1) for a one-week time cycle.

FIG. 15 shows a “seasonal control chart” 146, which is preferablygenerated by the analysis subsystem 30 of the meta-application 20 forsome or all of the monitored state metrics from the deployment 10. Forexample, seasonal control charts can be generated for those statemetrics that are known or observed to behave cyclically. The chart 146shows an input telemetry signal 148 for a given state metric (shown as adotted line), and a normalcy band indicated by two lines 152. Thenormalcy band represents expected norms for a specific time of the,e.g., day, week, month, or year. In a preferred embodiment, if atelemetry data value falls outside the normalcy band, then correspondingfeatures 150 (shows as squares) are registered, such as in the telemetrydatabase 26. In a preferred embodiment, each of the upper and lowerthresholds of the normalcy band can be characterized by azero-confidence level T₀ (corresponding to a feature confidence ofzero), a trigger-confidence level T_(c) (corresponding to a featureconfidence of c), and a full-confidence level T₁ (corresponding to afeature confidence of 1). It will be understood that the confidencelevels preferably comprise fluctuating waveforms. For ease ofillustration, FIG. 15 only shows the full-confidence levels T₁.

In one embodiment, the waveforms of the illustrated seasonal controlchart 146 are computed according to the following method. However,skilled artisans will understand from the teachings herein that othermethods for computing seasonality waveforms can be used. In oneembodiment, the analysis subsystem 30 lets a variable P be the period ofthe seasonal control chart (e.g. the time cycle) C. The seasonal controlchart contains points (xi, yi). The distance between two times x and xiis given by the following equation:

${d( {x,x_{i}} )} = {{( {x - x_{i}} ) - {{{round}( \frac{x - x_{i}}{P} )}P}}}$This is ordinary Euclidean distance reduced modulo P. Kernel smoothinguses a nearest neighbor approach to determine the smoothing function. Afunction S(x) is defined as the c closest points of C to x, the cnearest points (x_(i), y_(i)) to x as measured by d(x, x_(i)). The“bandwidth” about x is given by:Δ(x)=max(d(x,x _(i)),(x _(i) ,y _(i))εS(x))The weights of the kernel smoother are

${{w( {x,x_{i}} )} = {W( \frac{d( {x,x_{i}} )}{\Delta(x)} )}},$where W(t) is an even function that peaks at t=0 and approaches zero as|t|→0. The function W(t) can be chosen as:W(t)=(1−t ²)²If mu (μ) is the mean of the data in the chart 146, then the μ functionμ(x) is given by:

${\mu(x)} = \frac{\sum\limits_{{({x_{i},y_{i}})} \in {S{(x)}}}{{w( {x,x_{i}} )}y_{i}}}{\sum\limits_{{({x_{i},y_{i}})} \in {S{(x)}}}{w( {x,x_{i}} )}}$If sigma (σ) is the standard deviation of the data in the chart 146,then the sigma function σ(x) is given by:

${\sigma(x)}^{2} = \frac{\sum\limits_{{({x_{i},y_{i}})} \in {S{(x)}}}{{w( {x,x_{i}} )}( {y_{i} - \mu} )^{2}}}{\sum\limits_{{({x_{i},y_{i}})} \in {S{(x)}}}{w( {x,x_{i}} )}}$Mu and Sigma are finally used to determine if a future data point fallsoutside of expected norms for a specific time of the day, week, month,year, etc. When a telemetry signal falls outside of these control lines(normalcy bands), a feature is generated, just like the control chartmodel (FIGS. 12A-C).

Discrete Signals

Some telemetry signals are “discrete,” meaning that they are made up of(x_(i),y_(i)) points where y_(i) take on discrete values. For example,signals consisting of service state values (stopping, paused, running)or event ID's are discrete signals. Since discrete values are notnecessarily numerically comparable, numerical charts may not apply todiscrete signals.

A “discrete chart” can be used to convert real-time discrete signalsinto features that can be analyzed by the problem detector 38 (FIG. 1).In one embodiment, a discrete chart (or an associated algorithm) worksby checking whether measured y_(i) telemetry values are members of aspecific set D of discrete values. If the y_(i) values of the real-timediscrete signal are members of the set D for a sufficient number ofsamples and a sufficient amount of time (the sustain samples N_(S) andsustain time T_(S)) then a feature is generated.

FIG. 14 shows discrete chart 200 in accordance with one embodiment. Theillustrated discrete chart 200 analyzes a discrete telemetry signal thatis able to have, at any given time, one of four different values. Thepossible values are denoted as 203, 205, 206, and 208 (illustrated asrectangles with different cross-hatchings). An algorithm tests thetelemetry signal for membership in the signal value states 203, 205,206, and 208. In this example, during time intervals t₁, t₂, t₃, t₄, t₅,and t₆, the telemetry signal has signal values 203, 205, 206, 208, 205,and 203, respectively. Suppose the algorithm at work is interested ininstances in which the telemetry signal has value 206. Accordingly,features 210 (represented as a broken horizontal line) are generatedduring interval t₃. Features 210 are preferably only generated if thetelemetry signal has value 206 for a sufficient amount of time (thesustain time T_(S)) or a sufficient number of samples (sustain samplesN_(S)). Skilled artisans will appreciate that discrete charts can have avariety of different forms and can test for any number of differentsignal values.

Other types of feature detection methods can also be employed, such asmonitoring application error logs and conducting unit tests (e.g., byusing “shims”) on components of the application deployment 10. A fewexamples of features are shown in the table below, for an embodiment inwhich the meta-application 20 monitors and manages a deployment 10 ofMicrosoft Exchange™. In the table, each row is a specific feature or“feature predicate” (explained below in the Problem Detection section).The “Name” is the name of the feature. The “Type” describes the methodemployed to detect the feature. The “Telemetry Meter” is the specificstate metric from which the feature is detected. It will be appreciatedthat a feature need not always stem from a particular monitored statemetric.

Name Type Telemetry Meter Description CPU Control Chart Machine.CPU Usesthe control charts to determine “abnormal” behavior in CPU utilizationError Error Log N/A Creates a feature whose properties contain theinformation from the error message in the Exchange log Process ControlChart Process.ThreadCount Uses the control charts to determine Thread“abnormal” behavior in the number Count of threads used by a specificprocess CPU Trend Chart Machine.CPU Determines when the CPU Increasingutilization is consistently increasing Login Unit Test/ N/A Determinesif it is possible to login Shim Shim to an Exchange mail using OWA(Outlook Web Access ™) Mail Flow Seasonal MailMessagesPerSecondDetermines if the current mail flow Control Chart is not “normal”

Principle Component Analysis

In one embodiment, the analysis subsystem 30 first uses PrincipleComponent Analysis (PCA) to reduce the dimensionality or the amount ofdata in a set of telemetry signals fed into the feature detector 36. PCAis a mathematical technique for reducing the dimensionality of a datasetwithout losing useful information. Thus, a plurality of metrics gatheredat each specific point in time can collated into one data point withvalues for each dimension (e.g., CPU, page faults per second, etc.),including time. This data set can be fed into a PCA algorithm to producethe reduced data set. The reduced data set has the same basic trends andcharacteristics as the input telemetry, but much less data. Thus, PCAcan be considered a “noise eliminator.” PCA methods are well known inthe art.

Prediction and Resource Management

Prediction is the act of guessing future values for some stream oftelemetry data. The meta-application 20 can use prediction methods for avariety of purposes associated with managing a deployment 10, such aspredicting the exhaustion of fixed resources (e.g., disk space),optimizing resource utilization (together with “provisioning”), andperformance optimization. Predictions can be made about specific statemetrics, the prediction of which might require multiple streams oftelemetry. For example, a potential use of prediction is to predict theamount of free disk space given a list of disk performance metrics suchas “disk writes/per second” or “current disk usage.” In this example,several streams of disk-related telemetry would be used as input.

In another embodiment, the analysis subsystem 30 predicts the futurebehavior of a state metric by computing a mathematical model of themetric's telemetry signal as a function of time, as described above inthe Feature Detection section of the present application, and thensimply computing the metric's value at a given future time t. Skilledartisans will appreciate that other types of prediction methods can beemployed.

As mentioned above, three exemplary usage cases for the predictionalgorithm are predicting the exhaustion of fixed resources, optimizingresource utilization or “provisioning,” and performance optimization. Inpredicting the exhaustion of fixed resources, a specific metric such asfree disk space or network utilization can be predicted to warn ofpotential problems with the current deployment 10. For example, themeta-application 20 might predict that network traffic is growing at acertain rate and that in four to six months problems may arise fromnetwork bottlenecks.

The second case involves provisioning. Provisioning is the process ofdetermining the ideal way to distribute resource usage across severalresource providers (e.g., the CPU is a resource provider). Futureresource utilizations are used as the input to the provisioningalgorithm instead of the current rates of resource utilization. Thisallows the meta-application 20 to better predict good distributions ofresources for some time in the future, instead of an ideal distributionfor the current situation.

The third case involves optimization of the managed application 10.Usually, infrastructural applications have a variety of tuningparameters that can be used to improve performance in different hardwareand network environments. For instance, the size of the TCP(Transmission Control Protocol) sending queue in the OS network stackwill have different optimal values in different networks. Accordingly,the meta-application 20 can use the prediction algorithm to determinethe optimal settings for these tuning parameters.

Detection of Problem States

Problem Logic Overview

In preferred embodiments, the meta-application 20 stores, in itsknowledge base 22, definitions of application “problems,” which areknown problematic states of the managed application 10. Once themeta-application 20 has identified unusual or anomalous features, theproblem detector 38 uses problem identification algorithms to attempt tomatch logically defined combinations of features to problems. Theparticular knowledge encoding methodology and knowledge evaluationmethods that the meta-application 20 uses to detect problems isgenerally referred to herein as “Problem Logic.”

Problem Logic preferably uses an advanced “incremental query processor”configured to very quickly match a logical combination of features toproblems defined by the Problem Logic rules stored in the knowledge base22. When a feature is triggered, Problem Logic preferably uses a“discrimination network” (described below) to quickly determine whichlogic rules are potentially affected; however, a discrimination networkis not absolutely required. Problem Logic may also evaluate rawtelemetry data for purposes of detecting problems. Also, as features areadded and removed from the feature list (preferably stored in thetelemetry database 26), the query processor reconfigures itself tooptimize problem detection. Matched problems are added to a “problemqueue” (PQ). Each problem is assigned a “severity” and matched problemsare sorted by severity in the problem queue. The meta-application 20 canchange problem severity as it rates the impact of problems on thedeployment 10 and also as it gets updates from the update server 56(FIG. 2). Also, the associated feature that caused the problem may bumpup the severity of the problem. For example, a feature resulting from atelemetry signal diverging from its baseline normalcy band by sixstandard deviations might produce a problem with a higher severity thanif the signal diverged from its normalcy band by only two standarddeviations.

This section now proceeds by describing the theory behind the logicaland syntactic structure of the Problem Logic used in a preferredembodiment of the meta-application 20. The Problem Logic is embodied inthe logic rules stored in the knowledge base 22. In a preferredembodiment, the Problem Logic employs a language that is a modificationof First Order Logic, and which includes temporal, causal, and modaloperators. This language is used to encode the known problems'descriptions into the logic rules, which Problem Logic executes todetermine if any of the encoded problems are currently present withinthe deployment 10.

The meta-application 20 is preferably configured to analyze and quicklyrespond to large amounts of data. Accordingly, Problem Logic ispreferably fast enough to be used in a real-time system. To accomplishthis goal, Problem Logic is implemented by logic circuits similar to thehardware logic circuits on the computer chips of modern day computers,which are known to be fast. The Problem Logic circuits are not quiteidentical to hardware logic circuits because Problem Logic circuits pushmore than single bits of knowledge at a time along their “wires,” whichare preferably virtual.

Some definitions are now provided for ease of understanding of thefollowing subject matter, which describes only a preferred embodiment ofthe Problem Logic. A logic rule or simply “rule” is a logical formulacomposed of predicates, logical operators (such as AND, OR, THEN, etc.),mathematical operators (such as less than, difference, sum, etc.), freevariables, and constants. The formula describes how to recognizeproblems of the managed application 10. A “predicate” is a rulecomponent that represents the existence of a single concept within thedeployment 10. A predicate has a name and some number of arguments(which can be free variables or constants). An example of a predicate isserver_version(?server, “6.5”), wherein “server_version” is thepredicate's name, and “?server” and “6.5” are the arguments. In thisexample, “?server” is a free or “unbound” variable representing a server12 (FIG. 1) of the deployment 10, and “6.5” is a constant representingversion 6.5 of the server. A “bound” variable is a free variable in arule that has been assigned a constant value. An “unbound” variable is afree variable in a rule that has not been assigned a value and thus canmatch any value of the right type.

A “closed atomic formula” is a predicate whose arguments are allconstants (i.e., none of the arguments are free variables. Themeta-application 20 generates closed atomic formulae usually byanalyzing the deployment 10 and producing predicates that representdeployment state. A “gate” is an internal Problem Logic construct thatimplements a rule connective (like AND gates or OR gates). Inputs passthrough gates as the rule's formula is evaluated. Gates process theinputs according to the gate function (AND, OR, etc.) and then produce asingle output (which may be an input to another gate). In someembodiments, rule confidence levels (discussed below) are calculated andpropagated within the gates.

An application model object is a single entity instance from the schemaof the application model 24.

“Rule triggering” or “matching” refers to the situation in which theproblem detector 38 has successfully evaluated a rule's logical formulaand the evaluation has returned a value of “True.” This means that theProblem Logic has detected a problem within the deployment 10. There canalso be a confidence value on the rule. “Predicate triggering” refers tothe situation in which a predicate is able to determine all possibleinstances in the deployment 10 that have its current set of argumentsand can feed all of these instances into the Problem Logic.

A predicate's “contribution” is the importance of the predicate in arule, relative to all of the other predicates in that rule. Apredicate's “need” can have two states: “required” and “optional”. A“required predicate” of a rule is a predicate that must be true in orderfor the rule to make sense and be true. Typically, most predicates arerequired. An “optional predicate” of a rule is a predicate that need notbe true for the rule to be true. In other words, the rule will stillmake sense and match if the optional predicate is false. If thepredicate is true then the “true” evaluation of the rule will havehigher confidence. The concept of contribution is discussed more fullybelow. A predicate's “significance” is used to calculate whether a nonunit confidence rule triggering is a false positive. The concept ofsignificance is discussed more fully below.

A “constant confidence” is a value attached to a constant, whichindicates how strict a match should be. For example, if a predicatecontains an argument “2.0” with a low assigned confidence, then a valueof 1.9 or 2.1 might still match. If the confidence is high, then perhapsonly a value of 2.0 will match. A “predicate confidence” is a valueattached to a predicate, which indicates the degree of truth orconfidence attributed to the predicate. A “rule confidence” is a valueattached to a rule, which indicates the degree of truth or confidenceattributed to a match of the rule. The concept of confidence isdiscussed more fully below.

An example will help illustrate the Problem Logic approach. Consider thefollowing logical formula that defines a logic rule:

-   -   OR(AND(P(1,?x),Q(2,?x)),AND(P(2,?x),Q(1,?x)))        FIG. 16 shows a Problem Logic circuit 156 for this formula,        comprising gates A-H. The patterns associated with the gates are        shown in the following table:

Gate Pattern A P(1,?x) B Q(2,?x) C P(2,?x) D Q(1,?x) EAND(P(1,?x),Q(2,?x)) F AND(P(2,?x),Q(1,?x)) GOR(AND(P(1,?x),Q(2,?x)),AND(P(2,?x),Q(1,?x))) HOR(AND(P(1,?x),Q(2,?x)),AND(P(2,?x),Q(1,?x)))

The logic circuit 156 consists of four “atomic gates” A-D (indicated assquares), two AND gates E and F, one OR gate G, and one rule gate H(indicated as a circle). The patterns of the atomic gates are the atomicformulas P(1,?x), Q(2,?x), P(2,?x), and Q(1,?x) that appear aspredicates in the formula defining the rule. The names of the predicatesare P and Q. Each predicate contains two arguments: a constant (either 1or 2) and a free variable ?x. The pattern of each atomic gate is an“open atomic formula,” because it contains at least one free variable asan argument.

The operation of Problem Logic circuit gates is now described. TheProblem Logic circuitry receives ground instance atomic formulae thatrepresent states of the deployment 10. For example, in theabovementioned rule, suppose the predicate P(1, ?x) by definition refersto an instance within the deployment 10 of a server 12 (represented by?x, a free variable argument) running version 1.0 (represented by theconstant 1 argument) of a particular software program. Suppose furtherthat the deployment 10 only includes one server 12 running this version:server1. Then a ground instance atomic formula P(1, server1) can be fedinto the atomic gates of the Problem Logic circuit 156 shown in FIG. 16.Ground instance atomic formulas can be constructed based on inputtelemetry or information obtained from the application model 24. Theground instance atomic formulas arrive at the atomic gates A-D of thecircuit 156, where there is the possibility that the pattern of anatomic gate may match the input. If the free variables of the rule canbe instantiated by a variable substitution in a way that the substitutedpattern becomes equal to the input, then there is a match and a “bead”of information is sent on through the Problem Logic circuit along alloutput wires of the atomic gate. The “bead” is preferably stamped withseveral pieces of information, including a time interval containing thetime of arrival of the input, a confidence indicating the degree oftruth of the predicate, the contribution of the predicate, thesignificance of the predicate, and the satisfying variable substitution.

In the logic circuit 156, if telemetry input P(1,3) is received, thefirst atomic gate A matches P(1,3) generating a bead of informationconsisting of substitution [[?x,3]] and a time interval [6:39 PM, 6:39PM]. Once beads are placed on wires of a Problem Logic circuit, there isthe possibility that they can join with beads on other wires' to triggerlater stage intermediate logical gates of the Problem Logic circuit.

An OR gate (e.g., the OR gate G of FIG. 16) preferably just copies anyinput bead it receives to its output wires. An AND gate (e.g., the ANDgates E and F) preferably checks if there are compatible beads (i.e.,beads that match the binding variables in common between the twoformulae) on all the other input wires. For instance, in the logiccircuit 156 of FIG. 16, if a bead of telemetry input P(1,3) is receivedat one input wire of gate E, and if a bead of telemetry input Q(2,3) isreceived at the other input wire of gate E, then the beads arecompatible because the variable ?x is bound to 3 in both beads. If thereare compatible beads on the input wires of an AND gate, the union of thetime intervals and the substitutions of every set of compatible beads isused to create new beads on the output wires of the AND gate. A THENgate preferably works similarly to an AND gate, but with the additionalcondition that the time interval of a bead on the first input wire ofthe THEN gate must precede the time interval of a bead on the secondinput wire of the THEN gate in order for the THEN gate to be triggeredand generate output beads. A rule gate (e.g., rule gate H) preferablyjust prints out the information of all the beads that it receives.

Each gate preferably also takes the confidence, contribution, andsignificance of all the input beads and calculates the confidence,contribution, and significance of the output bead. Thus, when a bead issent to a rule gate, there is a confidence, contribution, andsignificance value on that bead that represents those values for theentire rule. For example, an AND gate can take the minimum of theconfidences of its inputs and assign that as the confidence of itsoutput. An OR gate can take the maximum confidence of its inputs andassign that as the confidence of its output. Those skilled in the artwill also recognize that the confidence, contribution, and significancecalculations can be arbitrarily complex and can change dynamicallyduring runtime.

The meta-application 20 preferably employs an algorithm for propagationand generation of new beads. Whenever input is read from telemetry or anapplication model query, the input is applied to all of the atomicgates. Alternatively, a discrimination network can be used (see below)to determine all of the atomic gates of the Problem Logic circuitry thatcan possibly match the incoming ground instance atomic formulae. Ineither case, whenever any output bead is generated, by an atomic gate orby a later intermediate gate, a pair consisting of that bead and thewire the bead can be placed on is pushed onto a “to do” list. The “todo” list then looks like this:

-   -   [[bead₁, wire₁], [bead₂, wire₂], . . . , [bead_(n), wire_(n)]]

The analysis subsystem 30 preferably executes a loop while the “to do”list is not empty. Each iteration of the loop pops a bead/wire pair offthe “to do” list. The destination gate of the wire is then notified thatthe bead has arrived on the wire and the behavior function of the gateis allowed to (possibly) generate new [bead, wire] pairs that are placedon the “to do” list. Eventually, the logic circuitry acquiesces and thepropagation loop terminates. Once that happens, the Problem Logiccircuit is ready to read the next input.

The behavior function of a logic gate generates a finite number of newbeads on its output wires in response to the arrival of a bead on aninput wire. The number of these beads generated is bounded by the numberof output wires times the maximum of 1 and the product of the numbers ofbeads on the input wires. Additionally, Problem Logic circuits do notcontain loops. The finite output of logic gates in response to an inputand the absence of loops ensure that the propagation loop terminates.

Rule Formats

In preferred embodiments, Problem Logic has a flexible problemlogic-encoding format that allows for the most error free and expressiveway to represent logic rules. The encoding preferably allows for data tobe attached to any component of a rule, in order to increaseexpressiveness or optimize performance by tagging rule components withhints. Accordingly, constraints are preferably added to the logicalformulation of a rule to allow Problem Logic to automatically determinewhat queries (e.g., AM queries, telemetry queries, queries for theexistence of features) to make and what metrics to gather to see if therule is relevant and capable of being matched by the deployment 10.

The components of a rule are logical connectives (AND, OR, THEN, etc.),constants, free variables, and predicates. Each predicate preferably hasa predicate signature (defined by the predicate name and the number andtype of arguments it requires) that defines valid uses of the predicate,data describing how the predicate interacts with a rule, and constraintsdescribing when the predicate is most relevant. The variables havenames. The constants have values.

In evaluating a rule, the meta-application 20 looks at each predicateand its arguments and checks to see if that predicate is triggerable,meaning that the predicate is able to determine all possible instancesin the managed deployment 10 with the predicate's current set ofarguments and can feed the Problem Logic circuitry of the problemdetector 38 with all of these instances. Predicate arguments that arefree variables can be bound or unbound. If a free variable is unbound,the predicate triggering mechanism will bind the free variable when itsends new instances to Problem Logic. The predicate's free variablearguments become bound when a closed atomic formula (an incomingpredicate instance with no free variables) is input into the problemdetector 38. In this case, Problem Logic will match the input to apredicate, and any free variables in the predicate will be bound withthe corresponding value in the closed atomic formula. Predicatearguments can also be string or real number constants.

The following table describes the constructs used to generate ProblemLogic rules, in accordance with one embodiment.

RULE CONSTRUCT DESCRIPTION expr && expr Logical AND expr || expr LogicalOR expr1 THEN expr2 Expr2 occurs chronologically after Expr1 (expr)Parentheses can group expressions ?<name> A free variable, which can beused as a predicate argument or on its own value.[metadata = value]Generic way to attach metadata to a rule value value.[confidence =number] Attaches a confidence to a value. The default OR confidence is1.0, signifying absolute confidence that the value.[conf = number] valueis correct and should be matched exactly. predicate.[metadata_name =data]( Generic way to attach metadata to a predicate in a rule arg1,arg2, . . . ) predicate.[contribution = number]( Attaches a relativecontribution number to a predicate arg1, arg2, . . . ) (relative to allother predicates in the rule). This number OR can be in any range.Problem Logic will normalize it as predicate.[cont = number](arg1, itcalculates. The default value is 1.0 for all predicates. arg2, . . . )The args are constant values possibly adorned with a [confidence = x]tag. The args can also be free variables (denoted with a ?<variablename> construction). predicate.[need = optional OR Specifies if thepredicate is “required” or “optional” required](arg1, arg2, . . . )which drives the logic gate calculations. For example, requiredpredicates must exist in order for a bead to proceed through an AND gatebut optional predicates can be missing. The args are constant valuespossibly adorned with a [confidence = x] tag. The args can also be freevariables (denoted with a ?<variable name> construction).predicate.[significance = number]( Assigns a significance to thepredicate that is used in rule arg1, arg2, . . . ) confidencecalculation. For example, if a rule triggers with non unit confidenceand all its predicates have lower than a threshold significance then therule is deemed a false positive and not shown to the user. The args areconstant values possibly adorned with a [confidence = x] tag. The argscan also be free variables (denoted with a ?<variable name>construction). Any valid C expression involving The Problem Logicgrammar will use the same syntax as predicates, free variables, values,C. Note: For most rules and predicates it is far superior and Coperators (+, −, /, *, << to embed a constraint expression into thepredicate rather (left shift), >> (right shift), <, <= , than putting inthe logic (i.e., use “t_metric(METER_ID, >, >= , == ) GT, 10)” insteadof “t_metric(METER_ID, ?value) && ?value>10” because then the FeatureDetector 36 can filter all irrelevant predicates, whereas in the secondconstruction the Feature Detector will send ALL t_metric predicates(regardless of its relevance) and Problem Logic needs to filter out theirrelevant ones. Also, the Feature Detector can push the constraint downto the Telemetry Component 34, which can push it down to the monitors 14so that the meta-application 20 can optimize its network bandwidth andnot send any telemetry that does not meet the constraint.

Each predicate preferably has data associated with it that indicateswhether the predicate can trigger with a particular set of arguments(where each argument is associated with information whether it isallowed to be bound or unbound). There may be multiple sets of argumentsthat are valid for a predicate. In general, it is preferred to have onlyone set of arguments so that the knowledge encoder can more preciselydictate which version of a predicate is used to match incoming atomicformulae.

When the meta-application 20 analyzes a rule, it scans all atomic inputsto the Problem Logic circuitry and matches them against predicates inrules. Some of these predicates will have only constant arguments andthe match is easy, since it is only necessary to determine if theincoming atomic formula exactly matches the predicate. Other predicateswill have free variables (like ?server) as arguments, and the problemdetector 38 will match those predicates by assigning the value in theatomic formula to the free variable that is in the same argumentposition. This process will bind free variables.

Most knowledge base articles start with some constraints on what systemsmay be involved (e.g., server must be running Exchange 2003™). Theseconstraints can be encoded in a logic rule as a query of the applicationmodel 24, referred to herein as an “AM query.” An AM query can bind avariable by asking the application model 24 for information about thedeployment 10. In some embodiments, a rule essentially breaks down intoprerequisite AM queries that narrow down the list of application model24 objects that are involved in the rule, as well as predicates that canquery for telemetry or perform other probing on the application modelobjects from the prerequisite AM queries. In order to permit moreflexible rule formulations, the Problem Logic rule format preferablydoes not enforce splitting a rule into prerequisite predicates and therule body.

Rules are preferably constructed so that after a first variable isbound, it is easy to bind the other variables because it is possible tofind a predicate that links from the bound variable to another variablethat the triggered predicate can bind. Knowledge base articles typicallyalso have this natural flow in them. For example, a knowledge basearticle might specify that the problem occurs on Exchange 2003™ servers(one predicate, including a ?server argument, which can trigger withoutany other bound variables), where the “smarthost” is set (anotherpredicate that can trigger if the ?server argument is bound, which itwill be due to the first predicate), and the smarthost is not reachableby DNS (a telemetry predicate that can only trigger if given thesmarthost name and the server from which it is trying to resolve, whichthe first two predicates bound). So a knowledge base article oftennaturally facilitates cascading predicates that bind each variable suchthat the next predicate can be triggered.

Thus, Problem Logic is preferably itself responsible for telling themeta-application 20 what inputs to gather. Accordingly, there needs tobe a way to “seed” Problem Logic with those initial atomic formulae, andthe answer lies in the rules themselves. Each rule is designed such thatit has some predicates that can “trigger” in the absence of boundvariables in its argument list (i.e., it can trigger without any othercontext other than the arguments given during rule encoding). This canbe a predicate that has some constant arguments and some free variablearguments.

The predicate triggering procedure will take the constant arguments andgenerate all the closed atomic formulae that match the predicate. Anexample would be a predicate like “exchange_server_version(?server,“6.5”). In this case, the predicate is tagged as triggerable with onlythe second argument bound; thus, the triggering procedure will find allExchange™ servers that are of version 6.5, and will produce closedatomic formulae for each one of them, producing input atomic formulaelike “exchange_server_version(server1.exchange.com, 6.5).” Thesetriggerable predicates trigger and send in new atomic formulae that thenbind the free variables in their arguments. Other predicates, whichdepend on having those variables bound, can then be triggered, causingmore free variables to bind until all free variables are bound and allpredicates in a rule can trigger.

Note that just because a predicate can trigger does NOT mean that itwill pass an atomic formula into Problem Logic. Triggering means thatthe predicate has enough data to find out if it is true for thedeployment 10. If it is not true, the predicate will not pass an atomicformula into Problem Logic, and usually this means that the rule willnot trigger (depending on the logic of the rule).

So rule encoding preferably ensures that a rule has enough “seed”predicates to begin the input gathering for evaluating the rule.Encoding also preferably ensures that there is a valid sequence oftriggering that allows all free variables in the rule to be bound.Encoders can be given an XML file that describes all predicates and theset of arguments each predicate needs in order to trigger. Encoders canuse this information to choose the right predicates to ensure that themeta-application 20 can automatically match the rule.

As an example, consider the following logic rule (for simplicity, allpredicate and rule metadata are omitted in this example):

-   -   AND(A(?srv, “6.5”), B(?srv, ?disk), C(?disk, “FreeSpace”, LT,        “50%”))        This rule includes three predicates: A, B, and C. It is known        that A can trigger with its first argument unbound and its        second argument bound. B can only trigger when “?srv” is bound        and “?disk” is unbound. C can only trigger when “?disk” is bound        and its other arguments are bound to values (in this example,        “LT” is a logical connective meaning less than). When the        problem detector 38 initially evaluates this rule, it determines        that B and C cannot trigger. If A also cannot trigger then the        rule would be flagged as invalid (a validation tool can be used        to prevent such a rule from entering the system in the first        place). Assume that A can trigger. The triggering procedure for        A is called and then all instances of A that are true for the        deployment 10 are passed into the corresponding Problem Logic        circuit. When an instance of A is input, this will bind ?srv to        a value. For example, suppose that A requires a server 12        (FIG. 1) running Microsoft Exchange™ version 6.5, and that the        deployment 10 includes a server1 running this version. This        instance will be fed into the logic circuit, and the ?srv        variable will become bound to “server1.” The next time the        problem detector 38 analyzes the rule it will see that ?srv is        bound. Now B can trigger because ?srv is bound, but C cannot        because ?disk is not bound. B triggers and all instances of B        that match are passed in as closed atomic formulae. When an        instance of B is input, it will bind ?disk. For example, B might        simply require the existence of a hard disk on the server bound        from predicate A. If server1 has a disk 1, then feeding        corresponding atomic formulae into the logic circuit will bind        ?disk to “disk1.” Next, the problem detector 38 will evaluate        the rule and see that ?srv and ?disk are bound. Now C can        trigger because ?disk is bound. Because most servers will not        have disks with FreeSpace<50%, even though C can trigger, it        will usually not produce new instances. However, in this case        assume that it does. This will cause the rule to trigger (i.e.,        be “True”) because the logic of the rule (all predicates must be        true) has been fulfilled. Note that the rule is constructed such        that there is a valid sequence of predicates that will bind        variables in a particular order to allow all predicates to be        tested.

The order of predicates in a rule can help the problem detector 38figure out what predicates to initially attempt to match. Predicateshave a cost associated with a particular predicate/argument set pair andthe problem detector 38 preferably uses this to determine whichpredicates to try first (it preferably tries the least costly predicatesfirst). When all the predicates of a rule have the same cost, theproblem detector 38 can be configured to use the order in which thepredicates appear in the rule to determine which predicate to try first(i.e., the earlier a predicate appears, the more likely it will be triedfirst). In other embodiments, the problem detector 38 chooses whichpredicate to try first based on cost, such that encoders of knowledgeneed not worry about the order of the predicates. In fact, in many casesthe cost of a predicate is a dynamic value that may change over time.For example, an AM query may be expensive at the start of operation ofthe meta-application 20, but after results are cached it may becomecheap. As another example, a telemetry predicate (i.e., a predicate thatasks for certain telemetry) may be initially expensive, but as otherrules ask for the same telemetry predicate it may become cheap tosubsequent rules.

Discrimination Network

To actually evaluate the Problem Logic rules, a “discrimination network”can be built from the rules and used to evaluate them simultaneously.When a feature is created, the problem detector 38 preferably uses thediscrimination network to determine which rules to evaluate. In otherwords, the discrimination network allows the problem detector 38 toquickly determine which rules might possibly care about a given feature.Thus, a discrimination network can be thought of as an index mappingfeatures to rules. It will be understood that some embodiments of themeta-application 20 do not include or use a discrimination network. Itwill also be understood that the discrimination network described belowis just one embodiment of a discrimination network, and other variantsare possible.

Describing a discrimination network is most easily accomplished throughan example. FIG. 17 shows an example of a discrimination network 158.The discrimination network 158 is an index into a database of key-valuepairs, where the keys are open atomic formulae possibly containing freevariables. Each key represents any predicate or sub-predicate whoseexistence indicates that a particular rule may be affected if thatpredicate is passed into Problem Logic. The illustrated discriminationnetwork 158 associates values with the following keys: P(1,2), P(1,?y),P(?x,2), Q(?a,?b), P(1,R(?z)), and Q(?x,S(3,4)). The illustrateddiscrimination network 158 is a tree with labeled edges and labelednodes. The edges leading to children of any given node always havedistinct edge labels. Edge labels can be (1) a constant or functionsymbol of the logic, (2) X, representing a variable, and (3) T_(i), anode label in the discrimination network, representing a subterm.

A preferred algorithm for creating or locating the discriminationnetwork associated with a particular n-ary term f(t₁, . . . , t_(n)) is:

-   -   (1) Create or locate the discrimination network node T₀ that is        a child of the root node connected by edge labeled f.    -   (2) For i=1 to n, compute edge label k_(i) corresponding to        subterm t_(i) and create or locate the discrimination network        node T_(i) that is child of node T_(i−1) connected by edge        labeled k_(i).    -   (3) Create or locate the discrimination network node T_(n+1)        that is child of node T_(n) connected by edge labeled with the        special label STOP.        A preferred algorithm for computing the edge label corresponding        to a term t is:    -   (1) If t is a constant, the edge label is t.    -   (2) If t is a variable, the edge label is the special label X,        representing a variable.    -   (3) If t is a non-atom, the edge label is the discrimination        network node label of the node reached by entering t into the        discrimination network.

With continued reference to the discrimination network 158 shown in FIG.17, the following describes a preferred method of locating thediscrimination network node associated with term Q(?x,S(3,4)). Therelevant part of the discrimination network is shown in FIG. 18. Themethod begins with the term Q(?x,S(3,4)). The root node is N_(o). Thechild off the root node N₀ connected by edge labeled Q is N₁. The edgelabel corresponding to variable ?x is special label X. The child offnode N₁ connected by edge labeled X is N₂. The edge label correspondingto subterm S(3,4) has to be computed by a recursive call whichdetermines that the node index reached by entering S(3,4) into thediscrimination network 158 is T₂. The edge label corresponding tosubterm S(3,4) is T₂. Continuing the entry of Q(?x,S(3,4)), the childoff node N₂ connected by edge labeled T₂ is N₆. Finally, the child offnode N₆ connected by edge labeled by special label STOP is N₇.Therefore, the discrimination network node corresponding to Q(?x,S(3,4))is N₇.

The following describes a preferred embodiment of fetching informationout of a discrimination network. The objective of information retrievalis to submit an atomic formula f to the discrimination network and thenretrieve all discrimination network nodes corresponding to atomic gatepatterns g that could possibly match f. Each discrimination network nodestores a list of atomic gates of the Problem Logic circuitry that needto be tested in case the discrimination network node is retrieved.

Consider the following example, with reference to FIG. 19. Suppose it isdesired to retrieve all the discrimination network indices for inputformula P(1,R(5)). The preferred approach is to advance a list ofindices through the discrimination network as P(1,R(5)) is consumed.This approach is also recursive, as determining lists of indices forsubterms may also be necessary. The method begins with the list ofindices [N₀], the singleton list containing the root node of thediscrimination network. The input formula being consumed is P(1,R(5)).So, for each node N in the list [N₀], the method proceeds by looking fora child connected by edge labeled P to form the next list, which is[N₈]. Next, the “1” subterm of P(1,R(5)) is consumed. Since the “1” is aconstant, for each node N in the list [N₈] the method involves lookingfor a child connected by edge labeled 1 or X to form the next list,which is [N₉,N₁₆]. Since variables can match 1, the method fetches nodesled to by edges labeled X. Next, the R(5) subterm of P(1,R(5)) isconsumed. Since R(5) is not an atom, this is less straightforward thanthe previous step. First, possible edge labels corresponding to R(5) aredetermined. This is accomplished by a recursive call which returns alist of possible keys [T₁,X]. So, for each node N in the list [N₉,N₁₆],the method looks for a child connected by edge labeled T₁ or X to formthe next list which is [N₁₂,N₁₄]. Since the term P(1,R(5)) has now beenconsumed, the method proceeds by looking, for each node N in [N₁₂,N₁₄],for a child connected by edge labeled STOP to form the next list, whichis [N₁₃,N₁₅]. The candidate matching atomic gates stored at N₁₃ and N₁₅are the atomic gates having patterns P(1,?y) and P(1,P(?z)). Thesepatterns are two of the six patterns used to create the discriminationnetwork example in FIG. 17.

After the discrimination network facilitates retrieval of alldiscrimination network nodes corresponding to atomic gate patterns gthat could possibly match input f, the input f is submitted as input toeach of these atomic gates of Problem Logic in turn. Each inputsubmission to an atomic gate may generate a match, a bead of informationto be sent out on all output wires, along with further propagationthrough intermediate logical gates.

Predicate Metadata

Some third party applications (i.e., other than the managed application10) provide numerous methods for instrumentation and monitoring, whichcan be used by system administrators to maintain a deployment 10. Themeta-application 20 can preferably utilize these streams of data tomonitor the health of the deployment 10. However, continuouslymonitoring every stream would place undo strain on the application 10itself and the network infrastructure in which it is deployed. Thus, themeta-application 20 preferably chooses which streams provide the mostvalue and when to listen to each stream. The Problem Logic's activestate is preferably used with other metadata to determine which feedsare currently the most vital.

Problem Logic, embodied within the problem detector 38 and the logicrules within the knowledge base 22, can take closed atomic formulae andmatch them against rules. But this means that Problem Logic must be fedall relevant formulae about the deployment 10 before all matching rulesfor that deployment can be produced. It is desirable to detect allpossible rule matches, because a single undetected rule match maycorrespond to a problem that brings the system down.

In order to comprehensively detect rule matches, Problem Logic ispreferably fed all relevant predicates that the deployment 10 cangenerate. To do this, Problem Logic evaluates each rule and determineswhat metric measurements (or functions of metric measurements) need tobe enabled and what database queries (e.g., AM queries, queries to thetelemetry database 26) need to be executed. Each rule is a logicalcomposition of predicates. So by finding all relevant closed atomicformulae for a rule and feeding them into Problem Logic, the problemdetector 38 can determine if the deployment 10 has a problem describedby a rule. In embodiments of the meta-application 20, Problem Logiccannot detect a problem unless there is a rule for it, and that rule canbe analyzed to reveal what metrics and queries can be run to feed allrelevant atomic formulae into Problem Logic. This means that the ProblemLogic will not be able to take a random series of features and correlatethem, unless there is a rule that defines the correlation relationshipamong them. The RCA module 41 can correlate rule matches (i.e.,“problems”) and random features to application model 24 components thatmay require attention. Those skilled in the art will recognize thatother non rules-based algorithms can take a random series of featuresand produce a correlation and problem identification. For example, suchalgorithms can use information from the application model 24 to relatefeatures to components in the application model, using metadata in theapplication model 24 to direct analysis.

Predicates in Problem Logic play dual roles. The first role is to definea matching mechanism for a rule. Closed atomic formulae (which arepredicates with no free variables) are fed into Problem Logic andmatched against the predicates that comprise a rule. To enable matching,the rule predicate needs to have a name and arity, and its argumentterms need to be constants or free variables. The second role of apredicate is to define how Problem Logic can automatically generateclosed atomic formulae from a predicate in a rule. In this case, thepredicate preferably has enough metadata associated with it to generateall possible closed atomic formulae relevant to the deployment 10.Problem Logic preferably creates the closed atomic formulae usingmetadata associated with the predicate, which indicates how to generateall relevant possibilities.

Note that it may be necessary for some of the predicate argument termsto be assigned a specific value before the predicate can generate closedatomic instances of itself that are specific to the deployment 10. Forexample, if a “cpu_slow(?srv)” predicate is needed, it cannot begenerated until the meta-application 20 knows the deployment server (the“?srv” variable) on which CPU usage should be measured. Once the server12 (FIG. 1) is known, the meta-application 20 can activate anappropriate CPU feature detector on that server. In some predicates,especially those specifying database queries (e.g., AM queries ortelemetry database queries), it may be sufficient if only some of thearguments are specified. For a query like “server_is_version(?srv,?version),” as long as the version is specified (e.g., “5.5” or “6.0”),the predicate can then generate all deployment servers 12 (the “?srv”variable) that match that version (e.g., by running an AM query likeshow_all_servers_of_version(“6.0”) to find all matching servers 12). Ifthe version is not specified, then the only viable option is toenumerate all servers of all versions in the deployment 10, which wouldbe expensive if in turn all feature detectors on all servers areactivated. In a preferred embodiment, a predicate's metadata lists thevalid sets of arguments that allow the predicate to generate atomicformulae itself (the process by which predicates generate closed atomicinstances of themselves is called “triggering”). AM query predicates cantrigger as long as a valid set of arguments is specified. It isordinarily not necessary for all of the arguments to be specified.

Other predicates, especially telemetry-based “feature predicates” (i.e.,logic rule predicates that specify the existence of features, which mayinvolve appropriate activation of the feature detector 36 and associatedtelemetry feature detection methods discussed above), need all argumentsspecified before they can generate their own atomic formulae. In apreferred embodiment, triggering for feature predicates is a two-stepprocess. First, Problem Logic specifies all of the arguments of thefeature predicate, which then is able to register a feature request(i.e., a request that the feature detector 36 look for the specifiedfeature). For example, the feature predicate may a request to checkwhether the CPU of a specific server is slow (e.g., check for “cpu_slow”on server “exmb1.Company.com”). Second, the feature detector 36 theninitiates the gathering of metrics necessary to fulfill the request. Inthis case, the feature predicate preferably has enough metadatainformation to allow the feature detector 36 to do this, which implies acoupling between the feature detector requirements for metricspecification and Problem Logic rules and predicates. If the specifiedfeature is found in the telemetry, the feature detector 36 sends thefeature information to the problem detector 38 (e.g., the featuredetector 36 can call a callback in the problem detector 38 with thefeature information), and the feature information is converted into aclosed atomic formula and fed into Problem Logic or sent to any otheralgorithm in problem detector 38. Of course, registration of a featuredetection request does not guarantee that the feature will be true andpassed in as a closed atomic formula. That depends on the deployment 10and its actual telemetry. Note that feature predicates have apotentially significant cost associated with them (monitoring resources,storage for historical data, etc.) and are preferably carefully chosen.

The following table lists some useful types of predicate metadata, in apreferred embodiment of the meta-application 20:

Predicate Metadata Description Name Name of the predicate. The samepredicate name may appear many times because there are many combinationsof argument states that are valid. Functionality Can be either an IDthat uniquely identifies a feature detector or a parameterized querystring like “(EXCHANGE[name = %1] and EXCHANGE[version = %2])”. Theparameters are the predicate arguments Argument 1 state Specified(argument must be bound to a value) or unspecified (argument must beleft unbound) Argument 1 type If state = specified, then the type of theargument. Type could be one of: string, float, integer, ApplicationModel object type Argument 2 state Similar to argument 1 state Argument2 type Similar to argument 1 type . . . . . . Argument N state Similarto argument 1 state Argument N type Similar to argument 1 type Cost Ameasure of the “cost” of triggering this predicate (normalized to be anumber between 0 (no cost) and 1 (very expensive)) with these arguments.This may be a dynamic quantity that changes over time. Severity A numberin [0,1] where 1 indicates total failure of all components affected bythe rule and a number in (0,1) indicates degradation of service to thecomponents (see discussion on Importance below) and 0 means no impact.Need [per rule] Two states: “required” or “optional”. Used by gates todetermine how to deal with the fact the predicate is missing as in inputto the gate. Contribution [per A numerical value in [0,1] where 0indicates little importance to the rule rule] and 1 indicates verystrong importance to the rule Used by gates to calculate overallconfidence in the rule. Significance [per A numerical value in [0,1]where 0 indicates that the predicate by itself rule] should not allow anon-unit confidence rule to display to the user and 1 indicates that ifthe predicate is missing that a non-unit confidence rule should notdisplay to the user. Basically a metric to allow Problem Logic to filterout “false positive” rule triggerings.

Thus, Problem Logic rules are preferably logical combinations of variouspredicates, each with different triggering requirements. Each ruleshould have at least one predicate that can trigger without anyarguments specified. Otherwise, the rule will not be able to “start”because no atomic formulae relevant to the rule have been passed in andno parts of the rule will match. And, the variables that are bound bythe initial “start” predicates should allow the other predicates totrigger, which will bind other variables, and allow more predicates totrigger, etc., until all relevant atomic formulae have been fed intoProblem Logic and the rule has matched or not. These are significant yetpreferred restrictions on the encoding of knowledge.

Seeding Predicates into Problem Logic

One way of relaxing the “start” predicate restriction is to “seed” themeta-application 20 with a fixed set of atomic formulae (generated basedon the deployment 10 configuration) that it always feeds into ProblemLogic, with the hope that these initial formulae allow rules to match.Logically, this “no arguments required” predicate restriction assumesthat the “seed predicates” are not completely unrelated and do notrequire multiple specified arguments making up a rule. If the seedpredicates were unrelated, this would intuitively mean that ProblemLogic would be looking at features or database queries that have nological or physical connection to each other in the context of a rule.

The “seeding” approach merely moves the task from determining howProblem Logic should analyze rules and automatically generate atomicformulae to determining how Problem Logic should figure out which atomicformulae should always be fed into it. One approach is to analyze eachlogic rule to determine how to generate “seed” atomic formulae. Rulesare assumed to have a “valid” construction, meaning that the rule hassome initial predicates that “start” the rule. These predicates bindvalues to variables, which then trigger new predicates that needed asingle variable to be bound, which the seed predicates provided. Thenthese secondary predicates bind more variables and more predicates cannow trigger, and so on until the rule is matched.

In a preferred embodiment of the seeding approach, Problem Logicperforms the following steps when it is initially activated:

-   -   1. Load all rules    -   2. Load predicate metadata    -   3. Identify all predicates in rules    -   4. Identify all seed predicates that can trigger    -   5. Choose seed predicates to trigger (based on minimum cost,        maximum problem detection probability, and/or other algorithms)    -   6. Trigger the seed predicates (may be asynchronous) and convert        results into closed atomic formulae    -   7. Send formulae into Problem Logic, which will bind new        variables and allow additional predicates to potentially trigger

This initial startup phase will analyze rules and “seed” Problem Logicwith deployment-specific atomic formulae that will then bind freevariables in rule predicates to specific values and allow Problem Logicto start matching rules. The seed predicates are typically produced bydatabase queries within the rules, which help to restrict the set ofdevices/circumstances that the rules match against. Thus, upon start-upof the meta-application 20, Problem Logic preferably begins sampling theuniverse of the deployment 10 and immediately restricts its analysisonly to those things that could possibly matter to a rule. It ispreferable to properly restrict analysis at this point, because if theanalysis is too restrictive, then the meta-application 20 may missproblems. However, if the analysis is too broad, the meta-application 20may unnecessarily flood the network with useless and expensive telemetrymonitoring requests.

Confidence

The meta-application 20 is preferably able to show a level of“confidence” that it has in a matched logic rule or problem. In oneapproach, the logic in Problem Logic is a traditional non-fuzzy logicwith behavior that depends on either true or false values. In thisnon-fuzzy logic approach, the confidence of a rule is a calculationbased on the confidence values assigned to each predicate of the rule.Confidence values of the predicates are preferably transformed as thepredicates pass through rule gates. However, the gates themselves do notchange their traditional logic behavior. For example, if a predicate hasa non-zero confidence of being true, then an OR gate will triggerbecause, as far as the OR gate is concerned, that input is true. Inother words, confidence is a value that is passed along during ProblemLogic operation, but does not otherwise affect Problem Logiccalculations.

In this non-fuzzy logic or “probability” approach, a predicate can onlyhave a true or false value, and a confidence value attached to thepredicate is a measure of the probability that the predicate is true.For example, a predicate having a confidence value of 80% means thatthere is an 80% probability that the predicate is true. Note that sinceany predicate that shows up in Problem Logic is assumed to be true, andfalse ones do not show up, this discussion centers on degrees andprobabilities of truth.

In an alternative, fuzzy logic approach, predicates are assigned degreesof truth ranging from 0% (absolutely false) to 100% (absolutely true).For example, a predicate having a confidence of 80% means that thepredicate is 80% towards true.

The type of confidence value (probability or fuzzy logic) of eachpredicate can depend upon the nature of the predicate. Predicates like“CPU_slow” (requiring that a certain CPU is currently slow) and“disk_full” (requiring that a certain disk is full) describe conceptsthat intrinsically have a vagueness that can advantageously be capturedin a confidence value. This confidence is more like a fuzzy logic truthvalue, involving increasing degrees of truth as the confidence valueincreases, as opposed to a situation where the CPU is either slow or notand the confidence value is a probability that the CPU is indeed slow.

Predicates involving database queries (e.g., an AM query) often have adefinite truth or falsehood associated with them, and in such cases donot need associated confidence values (i.e., confidence will always be100% or 0%). If there is some kind of constraint in the database query(e.g., count(set)>X), then the query could have an associated confidenceindicating how close the query came to the constraint. Predicatesinvolving telemetry queries (which are typically features where thetelemetry or metric is unchanged) also usually have a definite truth orfalsehood. However, if the telemetry query has a constraint, then themeta-application 20 can assign a confidence value describing how closethe query came to the constraint. For example, if the telemetry queryincludes the constraint “PerfMon_counter>10,” and if the counter is9.9999999999999, it may not be appropriate to compute that the predicateis false. Thus, a confidence value can help, where instead of theproblem detector 38 finding that the predicate is false with the counterequal to 9.9999999999999 (operationally, this means that the ProblemLogic circuitry actually does not receive the predicate at all, since itis false), Problem Logic computes that the predicate is true, with aconfidence value that is high but not 100%. Again, this is more like afuzzy logic degree of truth-value, rather than a probabilisticinterpretation of concrete truth.

Note that using a fuzzy logic approach causes Problem Logic to generatemore problems, because more predicates are allowed to pass through astrue than with strict two-value logic. Many of these rule triggeringswill have non-unit confidences. The meta-application 20 preferably has agraphical user interface (GUI) 29 (FIG. 1) that analyzes each problem'sconfidence computation to avoid making a low-confidence problem appearas a false positive (i.e., a declared problem that in reality does notexist). In addition, Problem Logic can use predicate significance todetermine which rule triggerings will be allowed. For example, oneimplementation could specify that if a rule triggers only withpredicates that have low significance then the triggering will not beallowed, thereby reducing the number of perceived “false-positives”.

Partial Problem Matching and Contributions

The meta-application's GUI 29 preferably shows problems that are“partially” matched so that the administrator of the deployment 10 canlearn about problems that are “almost triggered.” Problem confidence canadvantageously provide a measure of how close the partially matchedproblem is to triggering. Partial matches can also include thoserules/problems for which only some of the predicates have matched.

Suppose a rule evaluated by Problem Logic contains some predicates thathave matched (i.e., are true) and other predicates that have nottriggered at all. In displaying the problem associated with this rule,the GUI 29 can show the predicates that matched along with theirconfidence values. The GUI 29 can show the non-matched predicates ascompletely unmatched. Problem Logic does not really have any otherinformation about how close the non-matched predicates are to matching,because false predicates never even show up in Problem Logic processing.

In one embodiment, the meta-application 20 provides a measure of howclose a partially matched rule is to triggering by simply counting thenumber of atomic gates in a rule and computing a percentage equal to theamount of those gates that are matched. While this approach may proveuseful in many situations, it ignores the fact that logic rules havelogical constructions that constrain what atomic formulae will match arule. For instance, it is possible that a rule with nine of ten atomicgates matched can actually be less matched than a rule with only fouratomic gates matched but with the right values to allow the rule toproceed further in the logic evaluation. For example, consider thefollowing two rules R1 and R2:

R1: P1 and P2 and P3 and (P4 or P5 or P6 or P7 or P8 or P9 or P10)

-   -   R2: Q1 and Q2(Q1) and Q3(Q1) and Q4(Q1)        Regarding R1, assume that P4-P10 are true and P1-P3 are false.        With seven of the ten predicates true, the GUI 29 could report        that R1 is 70% matched. Regarding R2, assume that Q1 and Q2 are        true (the notation Q2(Q1) indicates that Q2 is a predicate that        depends on Q1) and Q3 and Q4 are false. With two of the four        predicates true, the GUI 29 could report that R2 is 50% matched.        However, logically R2 is “more true.” R2's logic circuit has an        AND gate with four inputs, two of which are true and the other        two of which are false (and the false predicates depend on Q1,        which is true). In contrast, R1's logic circuit has an AND gate        with four inputs, one of which is true (the input involving        P4-P10) and three of which are false. Therefore, simply        reporting the percentage of predicates that are true is not        necessarily the most accurate way to determine how close a        partial rule is to triggering.

In other embodiments, the meta-application 20 utilizes the confidence ofeach predicate of a rule and treats missing predicates in a special way,depending upon the types of gates in the rule.

For OR gates, Problem Logic preferably compensates for the fact that acurrently missing (i.e., false) predicate might trigger the OR gate.Problem Logic only feeds true predicates into the atomic gates of thelogic circuitry. If there are any non-empty input lines to the OR gate,then it preferably uses the maximum of all the confidence values of thetrue incoming predicates and ignores the missing inputs. If there wereno inputs (i.e., true incoming predicates), then a computed confidencevalue for the OR gate would be zero.

For an AND gate, a missing input predicate means that a term is falseand the AND gate should not trigger. However, in a logic rule with anAND connective, the input predicates to the AND gate may differ inrelative importance. Thus, if an input predicate is false, it may not beappropriate to simply set the confidence of the AND gate to zero.Preferably, Problem Logic can compensate for the fact that a missinginput predicate might be much less important to this particular ANDgate. Note that the relative importance of predicates in a rule dependsupon the rule. Some rules (or sub-rules) need all the predicates of anAND gate to be true in order for the rule (or sub-rule) to be true. Forexample, suppose a sub-rule requires that a particular server is runningMicrosoft Exchange™ AND the server's disk is slow AND the server's CPUis slow. Suppose further that the server's disk and CPU are slow, butthe server is not running Exchange™. In this case, the confidence of theAND gate really should be zero, because the sub-rule only applies toExchange™ servers. Now suppose the sub-rule also contains another inputto the AND gate, the additional input being some arcane Exchange™attribute that can perhaps be ignored in certain circumstances. In thiscase, if the server is running Exchange™ and its disk and CPU are slow,but the fourth predicate is false, it may be appropriate to compute anon-zero confidence.

In a preferred embodiment of the meta-application 20, relative“contribution” values or designations are assigned to each predicatewithin individual logic rules stored in the knowledge base 22. Thecontribution preferably defines the relative importance of the predicatewith respect to all other predicates in the rule. This allows ProblemLogic to process contribution through all gates of the circuit and notjust at the atomic gates. In one embodiment, Problem Logic also includesa “need” designation that includes the two states “required” and“optional.” In another embodiment, the contributions comprise numericalvalues. For example, the contribution can be a number between 0 and 1,wherein a value of 1 signifies an absolutely essential contribution anda value of 0 signifies no contribution (a value of zero is actuallyinappropriate, because it would mean that the predicate should notreally be an input into the gate). Problem Logic can use these numbersto determine how to adjust the confidence of an AND gate. If thecontribution for a missing predicate is tagged as “required,” then theAND gate will preferably produce a confidence of 0 (0% confidence thatthe AND gate output is true) because the missing predicate is essentialto the rule and is interpreted as false (the essential input wire to theAND gate has 0% confidence), which immediately makes the output of theAND gate false.

For instance, in the aforementioned example, the predicate describingthat the server is running Exchange™ is preferably assigned a need valueof “required,” because the rule only applies to Exchange™ servers. Thus,if the server is not running Exchange™, the AND gate confidence would becomputed to be 0%. If the need values of all of the missing terms (i.e.,predicates) are optional, then their contributions each preferably havea floating point value (e.g., a number closer to 0 than to 1). ProblemLogic can be configured to sum up the confidence values of thenon-missing terms and multiply by the ratio of the sum of contributionsof the non-missing terms over the sum of contributions of all terms,essentially normalizing the gate inputs based on contributions. So, inevaluating a rule or sub-rule, if a missing term is some arcaneExchange™ attribute, its contribution can be set to a small value andthe net effect would decrease the output confidence but not truncate itto 0. This makes sense because the missing term has a finite probabilityof making the AND output false. Thus, while the confidence that the ANDgate is true is reduced, since the contribution of the missing term tothe AND gate is minimal, Problem Logic preferably does not truncate theoutput confidence to zero, but instead decreases it by some smallamount.

Similar calculations can be done for an OR gate. In a preferredimplementation, rather than normalizing inputs they are simply summed,and the sum is clamped to 1.0 if it exceeds 1.0. This approach avoidsreducing the confidence of the output bead simply because new lowconfidence input beads were presented to the OR gate. This captures thespirit of the OR gate, which is that it triggers when any one input istrue, and other true (or partially true) inputs should not reduce theconfidence.

Those skilled in the art will also recognize that the confidencecalculations for gates can be arbitrarily complex and can changedynamically during runtime based upon things like feedback data on theefficacy of previous rule firings (e.g number of false-positives and thenumber of successful resolutions).

Problem Logic Operational Summary

The following describes what the Problem Logic components do when theyare running, in a preferred embodiment of the meta-application 20:

-   -   1. Accept incoming closed atomic formulae, each formula having a        confidence associated with it. Incoming atomic formulae come        from:        -   a. AM query callbacks. A callback is associated with each AM            query. The application model 24 will call the callback            anytime an application model state changes and the change            could potentially affect the query results. The callback            will look at the new results and compare it with the old            results, and if it sees any changes it will pass those            changes into Problem Logic as closed atomic formulae.        -   b. Feature Detector callbacks. A callback is associated with            each feature-detection predicate (i.e., a predicate that            requires the existence of a specific feature and asks the            feature detector 36 to look for that feature). The callback            will be called when a feature is calculated. The feature            will also have a confidence calculated. The callback will            convert the feature into a closed atomic formula with a            confidence value.    -   2. Pass atomic formulae into all rules that could possibly care        about them.    -   3. For each rule, use formulae to bind variables, creating        beads, and push the beads as far as possible from the atomic        gates to the rule gates.        -   a. For each gate, calculate the gate confidence of the            output wire. These output wires will be the input wires of            subsequent gates, so all gate inputs have a confidence            value.        -   b. Store each new variable binding on the rule.    -   4. If a rule gate output wire is reached, indicating that a rule        has matched, send the match to the remedy selector 40.        -   a. The rule gate output wire will also have a confidence,            representing a confidence that the rule has matched.    -   5. Propagate the beads of all rules as far as possible within        Problem Logic circuitry. For all rules, check to see if any new        variable bindings have been added. If so, then:        -   a. Generate all possible relevant variable combinations            using old variable bindings and the new ones        -   b. For each predicate, Problem Logic can calculate the cost            of triggering the predicate with each set of variable            combinations (each predicate provides this functionality)    -   6. Problem Logic chooses which predicate to trigger        -   a. Problem Logic bases its choice on an optimization            algorithm that considers the cost of the predicates and the            current value of each predicate to the rule (in this            context, “value” means the worth of the predicate in            resolving the logic of the rule to a trigger state). For            example, if there is just one more predicate at a certain            gate that is required to trigger a rule with high output            confidence, then it makes sense to trigger this predicate,            even though it might be expensive, versus a predicate at            another gate which will not trigger a rule or trigger it            with a low confidence.        -   b. This is where Problem Logic sequences predicate requests            to fulfill multiple conflicting requirements:            -   i. Predicate Request Sequencing: Minimize the cost of                rule matching by only turning on expensive predicates                when it most matters. Cost is calculated by the                predicate itself (based on predicate metadata) and is                not necessarily fixed. For AM queries, the application                model 24 may cache queries so that the cost of querying                information may decrease dramatically for subsequent                queries. For feature-detection queries, if the feature                detector 36 is already looking for a particular feature                based on a query from another rule, then the cost for                new rules to query for the same feature will be lower.            -   ii. Partially Matched Problems: Maximize visibility into                rule matching by turning on all possible predicates to                get the most accurate confidence number (identify those                predicates that, if true, would trigger the rule).                Because of the logical nature of the rule, not all                predicates are equally important in this regard. An                administrator of the deployment 10 can send “hints” to                Problem Logic, via the GUI 29, as to which rules need to                have complete information on partial rule matching. For                example, the administrator can be permitted to inform                Problem Logic that something is a problem, by                artificially triggering a feature, or that something is                not a problem, by turning off a feature predicate. Also,                the administrator is preferably able to select a                deployment device and ask for all partially or fully                matched problems and their confidences. This may                disallow short-circuiting AND gates and OR gates and may                also disallow other optimizations based on cost or                likelihood, because the meta-application 20 is now                concerned about the confidence of all predicates, in                order to calculate an accurate confidence.            -   iii. “Volume” control based on confidence: Change                predicate sampling frequencies (choosing from a set of                standard sampling frequencies to help simplify                implementation of telemetry component 34) based on                confidence that a rule is about to match (using                confidence calculation). If Problem Logic is very                confident that a rule is close to matching, increase the                sampling frequency for those predicates that are missing                and would allow the rule to match. This will generate a                new predicate request and may replace a previous                request.            -   iv. “Volume” control based on bandwidth: Change                predicate sampling frequencies based on monitored                bandwidth usage. Problem Logic rules are not too                sensitive to predicate sampling frequencies, so volume                control optimizations should not be too disruptive. This                will generate a new predicate request and may replace a                previous request.    -   7. Run the trigger procedure for all predicates marked for        triggering, which will register new callbacks with the feature        detector 36 and application model 24.    -   8. Old and new callbacks get called when new results are        available, which are converted to closed atomic formulae.    -   9. Send closed atomic formulae to Problem Logic and go to step        1, continuing the normal rule matching process.

Problem Logic Learning

In a preferred embodiment, the meta-application 20 is configured to“learn” about the success and failure of executed remedies, and adjustthe Problem Logic circuitry accordingly. A Problem Logic circuitassociates a confidence between 0 (low confidence) and 1 (highconfidence) to every matching problem. The confidence is calculated asif the Problem Logic circuit were a small feed-forward neural network.Each type of logic gate (AND, OR, etc.) has its own activation function(f_(AND), f_(OR), etc.). The activation function for an entire logiccircuit is a composition of the activation functions of the constituentgates. For learning purposes, it is beneficial for the activationfunctions to be sigmoidal functions that are multivariate, nonlinear,continuous, smooth, and generally monotonic functions. The logic gateactivation functions input confidences x_(i) fed forward by inputfeatures or input logic gates. Additionally, the logic gate activationfunctions also input tunable connection weights w_(i), which are thepredicate contribution values of Problem Logic. Thus, as themeta-application 20 learns about the success and failure of executedremedies, it can “tune” the predicate contribution values of ProblemLogic.

Consider the logic circuit shown in FIG. 16. A corresponding confidenceactivation function for the circuit is as follows:f(a,b,c,d,w _(a) ,w _(b) ,w _(c) ,w _(d))=f _(OR)(f _(AND)(a,b,w _(a) ,w_(b)),f _(AND)(c,d,w _(c) ,w _(d)))The artificial neuron appearing in a typical multilayer neural networkmay compute its output asy=f(w ₁ x ₁ + . . . +w _(n) x _(n) +b),where f is some universal basis function such as tanh. However, forpurposes of Problem Logic, it is preferred that f_(AND) and f_(OR)sigmoidal activation more approximately resemble classic boolean AND andOR functions. Accordingly, the following are chosen:f _(AND)(x,w)=1/2tanh(w ₀ +x ₁ w ₁ + . . . x _(n) w _(n))+1/2f _(OR)(x,w)=1/2tanh(w ₀ w ₁ ^(x1) . . . w _(n) ^(xn))+1/2

Problem Logic confidence calculations are preferably based onwell-established neural network theory, so it is possible to train theconfidence calculations of Problem Logic circuits via supervisedlearning, just as it is possible to train neural networks via supervisedlearning.

A Problem Logic circuit can be trained by providing a training set ofmatching problems and target confidences (generally either accept=1 orreject=0). A stochastic back-propagation algorithm, amounting togradient descent, can be repetitively applied to examples in thetraining set until sufficient convergence of the connection weights ofthe Problem Logic circuit being trained is achieved. The following is astochastic back-propagation algorithm:

Stochastic Back-propagation Algorithm:

initialize weights w, criterion θ, learning rate η;

while (true) {

-   -   x=randomly chosen training pattern;    -   for (i=1; i<=n; i++) {        -   w_(i)=w_(i)−η∂E(x,w)/∂w_(i)    -   };    -   if (∥∇E(x,w)∥<θ) break;

};

return w;

The above-shown algorithm includes the following variables: Theparameter x is the input feature confidences. The parameter w is theconnection weights. The parameter θ is the stopping criterion. Theparameter η is the learning rate. The parameter n is the number ofconnection weights. The function E(w,x) is equal to ½ (z−t)². Theparameter t is the target confidence. The parameter z is the calculatedconfidence, f(x,w). The parameter ∇ is (∂/∂w₁, . . . , ∂/∂w_(n)). Itwill be understood that if a feature is not present in the trainingpattern, then the confidence x_(i)=0 for the missing feature. TheStochastic Backpropagation Algorithm can be used to train or improve theconfidence calculation connection weights of a Problem Logic circuit.

Deployment Healing

Healing Overview

When Problem Logic matches a rule, it registers a problem and informsother modules of the meta-application 20. Since, in a preferredembodiment, there can be multiple active problems (i.e., problemsflagged as currently existing and for which resolution has not yet beenconfirmed), the meta-application 20 is preferably configured todetermine the relative “severity” of problems and sort the problems byimportance.

In a preferred embodiment of the meta-application 20, most or all of theproblems are encoded with a “severity” and a remedy that contains a listof possible plans. Such information can be stored in any convenientlocation, and preferably in the knowledge base 22 and/or plan database28. The remedy selector 40 preferably uses remedy selection algorithmsto globally review all active problems and their potential remedies andselect remedies for the most severe problems first. Each remedy can havea “resolution policy” that indicates how that remedy interacts withother remedies and problems. For example, a remedy may be “globallyexclusive,” which indicates that all less severe remedies (remedyseverity can be defined as the highest severity of all of the problemsattached to a particular remedy, it being understood that a given remedycan be selected for a plurality of different problems) and problemsshould be ignored until the meta-application 20 can first resolve thisparticular remedy. This would be appropriate for remedies that fixfundamental services, since many concurrent problems may actually beside-effects of the failure of the fundamental service and may beresolved simply by resolving the fundamental service issue first. Theresolution policy preferably also indicates how to verify whether theremedy actually worked and resolved its associated problem.

After reconciling all remedies and their resolution policies with theresolution policies of other currently active problems/remedies, themeta-application 20 preferably submits a list of remedy ID's to execute.Since the meta-application 20 might only have a partial ordering ofremedies by “severity,” it may be possible for multiple remedies to beclassified as “most important.” In this case, the remedy selector 40 canexamine its knowledge base 22 to determine if there aredeployment-specific hints (which the meta-application 20 may havegenerated over time) to select between remedies of otherwise equalseverity.

At this point the RCA module 41 can be accessed to determine additionalsorting measures to apply to the remedies, based on the causalrelationships among the rules that triggered and initiated theresolutions. This may provide an unambiguous ordering of resolutions.

If there aren't any deployment specific hints to select between remediesof otherwise equal severity, then the meta-application 20 can ask anadministrator of the deployment 10 to choose among the remedy options.Alternatively, the remedy selector 40 can be configured to simplyrandomly choose one of the remedies of substantially equal severity,particularly if they are deemed “non-catastrophic” (if some of theremedies have the potential to bring the system down, then it may bepreferred to leave the choice to the administrator). After a selectedremedy is executed, the meta-application 20 preferably utilizes a healthevaluation algorithm to determine how the remedy affected the health ofthe deployment 10. If the deployment health does not improve, the remedyselector 40 can simply choose another remedy (or ask the administratorto choose another remedy), and possibly attempt to undo the previouslyexecuted remedy and record its utility for the current system state. Inthis way, the remedy selector 40 can use the health evaluation algorithmto track remedy performance so that the next time the same problem (or arelated problem) is detected, the remedy selector 40 will have morecontext to choose among remedies.

After the remedy selector 40 selects a list of possible remedies, theirassociated remedy ID's are preferably sent to the automation subsystem32. The automation subsystem 32 is preferably configured to take ahigh-level remedy and map it to an “abstract” plan in the plan database28. The planning module 42 preferably then takes the abstract plan andinformation obtained from the application model 24 to produce adeployment-specific plan composed of low-level actions. This plan canthen be displayed to the administrator (via the GUI 29, an email, aweb-page, or sent directly to the administrator's network managementsystem as an SNMP trap, etc.) so that the administrator can execute theplan manually. Alternatively, if the administrator wishes, the plan canbe sent to the execution engine 44 to be executed in a consistent,reversible manner. Before executing the plan, the execution engine 44preferably makes sure that other plans do not conflict with this one.

During execution, each plan step is preferably a sequence of low-level“operators.” Operators are atomic actions that can be executed againstthe deployment 10. Each of these actions can be sent to an appropriatemonitor 14, which preferably executes the actions against the deployment10 and reports back as to whether the action succeeded in its intendedeffect. The execution engine 44 then continues executing plan stepsuntil completion. These actions are intended to change the behavior ofthe deployment 10, which may in turn change the telemetry metrics thatthe meta-application 20 monitors.

After a plan has been executed, the meta-application 20 preferablyattempts to learn whether the plan/remedy worked. Accordingly, theanalysis subsystem 30 continues to analyze new telemetry and, based onthe telemetry change, may adjust the predicate weights discussed abovein “Problem Logic Learning.” If the remedy worked, the featuresassociated with the problem should now disappear, and consequently theproblem will not be matched by the Problem Logic circuitry. At thispoint, the resolution policy associated with the executed remedy ispreferably still active, and asks the remedy selector 40 (or othercomponent of the meta-application 20) to determine whether the problemis still active. In response, the remedy selector 40 preferably runs a“resolution verification” procedure (associated with the remedy) toverify closure of the problem, and then deactivates the resolutionpolicy after positive verification. If the problem still persists, theresolution policy remains active and the remedy selector 40 preferablyruns a “remedy did not work” procedure to try alternative methods (theremay be multiple remedies associated with the problem or it may beappropriate to retry the remedy). If no alternative works, then themeta-application 20 preferably notifies the administrator of thedeployment 10, and further processing with respect to this problemceases until the administrator is able to address the issue.

Remedy Selection

The resolution policy for a remedy allows the meta-application 20 tomore explicitly manage the application control feedback loop to allowremedies to propagate their effects through the deployment 10. A typicalresolution policy will mandate that the meta-application 20 wait some Nminutes for the remedy to “work”. The meta-application 20 preferablynotes “global system health” just before executing the remedy. Globalsystem health is a numeric measure that encapsulates the current stateof the application deployment 10 and preferably assesses a combinationof application responsiveness, resource robustness, and other factors.During the remedy waiting period, any problems associated with theremedy can be “ignored” (i.e., the remedy selector 40 will not initiateremedy selection) to allow the already existing remedy to attempt tofinish.

Once the waiting period has lapsed, the meta-application 20 can thencheck to see if the problem for that remedy still exists. If it doesnot, the meta-application 20 can run a “check if remedy worked”resolution verification procedure of the remedy's resolution policy.This policy may simply indicate that the problem's non-existence isenough to declare success, or there may be additional verification stepsrequired. If a remedy is deemed successful, the meta-application 20preferably logs the effect of the remedy on global system health anddeletes the resolution policy from the list of currently activeresolution policies.

As explained above, if a remedy is found to be unsuccessful, themeta-application 20 preferably runs the “remedy did not work” procedureof the resolution policy associated with the remedy. If a remedyassociated with a problem has multiple plans, then the resolution policycan try each plan. If none of the plans work, then the meta-application20 can follow the “remedy did not work” procedure for the last plan.This policy may dictate that the meta-application 20 halt all processingon the problem and notify the administrator of the problem. Or it mayask the administrator how to deal with the failure to resolve theproblem (ignore the problem forever, ignore for some time, ignoreproblem until administrator indicates that a manual resolution has beenattempted, etc). Or it may simply retry the plan a certain number oftimes before giving up and then trying one of the other options if theplan simply continues to fail.

The remedy's resolution policy preferably also indicates how the planinteracts with other running plans. The remedy execution can be“globally exclusive,” which indicates that no other remedies may run onany component of the deployment 10 concurrently with this remedy. For adeployment 10 of Microsoft Exchange™, an example of a “globallyexclusive” remedy might be one that fixes an unresponsive DNS server;since so many other components are dependent on DNS service, it isimportant to resolve this remedy first, and it is likely that most otherproblems will be resolved as well. Also, some remedies may be verysensitive to other simultaneously running activities, and need globalexclusion to ensure safe operation. Remedies may also be “locallyexclusive,” which indicates that no other remedy may run on theparticular component (e.g., a server 12, a disk) that the remedy runson. In one embodiment, most remedies are “locally exclusive,” since thisis how good administrators attack problems (by trying one thing at atime on a server 12).

The meta-application 20 may force all remedies into global exclusion ifit senses that global system health is deteriorating at an unacceptablerate. In this case, there may be multiple remedies running while thedeployment 10 is deteriorating, and it may be desirable for themeta-application 20 to isolate the problematic remedy or remedies byrunning remedies sequentially rather than simultaneously. Themeta-application 20 can direct the automation subsystem 32 to suspend orabort all remedies. If suspending or aborting a remedy is not possible,then the meta-application 20 can wait until the remedy has completelyexecuted and then run remedies in global exclusion mode. Globalexclusion will allow the meta-application 20 to clearly determine howeach remedy is affecting the deployment 10.

When a remedy is selected for execution, there will typically already bea set of remedies and associated resolution policies in effect. Beforenew remedies are selected for execution, the remedy selector 40preferably checks all currently active resolution policies to see iftheir problems have disappeared. If they have, the “check if remedyworked” procedure can be run. Then the remedy selector 40 can select anew remedy and reconcile its resolution policy with pre-existing,currently active resolution policies. If the new remedy has a resolutionpolicy of global exclusion, then currently executing remedies can betold to suspend or abort themselves. Alternatively, if the new remedyhas a resolution policy of global exclusion, then the meta-applicationmay be configured to allow currently executing remedies to be completedbefore executing the new remedy. If the execution policy of the newremedy is local exclusion, then any remedies running on the componentthat is affected by the new remedy will be suspended or aborted, oralternatively those running remedies will be permitted to finish beforethe new remedy is executed on that component. With local exclusion,remedy selection can continue for each component that has not had aremedy selected yet.

After all remedies have been selected, the new remedies are run. Newtelemetry comes into the analysis subsystem 30 and generates newfeatures and problems. Then remedy selection begins again. For each newproblem, the remedy selector 40 preferably determines whether it isalready associated with an active resolution policy and whether theassociated remedy is in its waiting period. If it is still waiting, thenthe remedy selector 40 can ignore the new problem and allow the remedyto complete. If the remedy is past the waiting period and the problemstill exists, the remedy did not work, and the aforementioned “remedydid not work” procedure is run. Thus, each cycle of remedy selection iseither creating new resolution policies for new problems and remedies ormanaging currently executing problems and remedies. In this way, themeta-application 20 manages the life-cycle of remedies and is able tomanage sets of conflicting problems and remedies by consistentlychoosing to fix the most important problems first and postponing lessimportant problems.

As remedies achieve closure (either fixing their problems or beingdeemed unsuccessful) they are preferably rated according to how wellthey affect local health (on the component) and global health (acrossthe application deployment 10). This information is used to informfuture remedy selection decisions and may also be used by the “ProblemLogic Learning” algorithm to determine predicate weights.

The following table shows a few examples of problem-remedy combinationsfor a meta-application 20 that manages a deployment 10 of MicrosoftExchange™. In this case, the illustrated problems are based onMicrosoft™ Knowledge Base articles, identified by MSKB identificationnumbers. It will be understood there will typically be a large number ofsuch combinations in association with a meta-application 20.

PROBLEM MSKB ID REQUIRED FEATURES POSSIBLE PLANS Event ID's 454 and327065 Event Feature 454; Event MoveFilePlan: moves 9518 when attempt toFeature 9518; Various AM the streaming file from mount the informationqueries to locate the backup to correct store database information storestreaming directory on the file Exchange server Store.exe threads use267255 Trend feature: CustomPlan: changes up available memoryProcess.VirtualBytes is three registry values on increasing; Controlchart the misbehaving feature: Exchange server Process.ThreadCount istoo high; Event Feature 12800 Messages remain in 884996 Event Feature9003; Event CustomPlan: Reset the “Messages awaiting Feature 9004; EventFeature location of the archive directory lookup” 9035; Event Feature6004 file; CustomPlan: Turn SMTP queue in off message archiving Exchange2003 Server or Exchange 2000 Server

Plan Execution

A plan can be thought of as an abstract remedy that has been convertedinto a deployment-specific, instantiated sequence of steps and decisionfactors for executing the remedy. A plan can express a possible solutionto a problem, a “best” or sanctioned way to configure the deployment 10,or a commonly performed administrative task. Since a problem cansometimes have more than one possible solution, the meta-application 20uses remedies, wherein a remedy may comprise a set of plans with aresolution policy, as described above.

Plans may require “function arguments” that specify or request moredetails to complete the plan. For example, a “kill rogue process” remedyneeds the server 12 and process ID to execute. Each plan may beassociated with multiple problems or remedies, so simply passing theproblem information to the plan may not work because the plan would thenbe responsible for figuring out how to map its arguments from allpossible problems. Also, plan mappings to problems may change over time.Thus, plans preferably have a generic argument passing mechanism. Eachproblem preferably has associated attributes (e.g., metadata such asseverity, etc.), and the remedy can preferably determine its functionarguments by querying problem variables. This allows any plan to bemapped to any problem through a remedy, but only if the problem has allthe variables required for the plan. Since, by definition, the plan andproblem are related in the real world, this restriction will more thanlikely not be onerous. This may require that problems and plans agree onwhat each variable name represents. For example, if a problem is relatedto a certain process, the problem preferably uses the same name for theprocess ID that the plan uses to query for that argument (e.g.,“process_id”).

As explained above, after the analysis subsystem 30 has identified aproblem, the automation subsystem 32 is responsible for correctiveactions against the deployment 10. The illustrated automation subsystem32 includes a planning module 42 and an execution engine 44. Inpreferred embodiments, the planning module 42 manages, binds, andevaluates plans, and the execution engine 44 actually performs actionson behalf of the planning module 42.

In a preferred embodiment of the meta-application 20, plans aregraphically represented in the GUI 29 as object trees, wherein each nodein the tree defines a step or decision factor in the plan. In apreferred embodiment, a plan object tree comprises the following typesof nodes: A scope node is a container-type node, preferably containingdata such as arguments, metadata about the problem that the planattempts to resolve, or the actual Problem Logic formula associated withthe problem. A condition node is a decision factor node (i.e., a pointin the tree with multiple possible outcomes based on the results of aqueried input or data). A condition node can define a branch of the treebased on an expression. An interface node is an action-type node (e.g.,a point in the tree in which some action is executed against thedeployment 10). An interface node can define an interface to the system,such as an operator or query.

In a preferred embodiment, each tree node may contain metadatainformation that is used to render the tree and describe meaning to anend-user, and dependency and side-effect information used to determinehow a plan may conflict with best practices or other currently executingplans. Also, plans may have variables. Variables are used inexpressions, to pass parameters and return results from interfaces, andto keep active plan state.

Plans can preferably interact with the meta-application 20 throughinterfaces. A number of different types of interfaces can be provided.For example, a query interface can allow a plan to obtain informationfrom the application model 24. A plan can use an operator interface to aset of operators that define actions to be carried out against thedeployment 10. A feedback interface can allow a plan to presentquestions to a human administrator, the answers to which may be requiredto continue executing the plan. Runtime interfaces to the planningmodule 42 can provide general utility functions such as regularexpression parsing and notification of plan events. Also, plans can useplan interfaces to invoke child plans.

Plans can preferably be executed and/or rendered. Rendering a plan meansgenerating a set of human-readable instructions for an administrator tofollow. In preferred embodiments, plan object trees may be transformedduring processing. For example, a plan may record or display resolvedapplication model queries, identify deployment-specific branches, etc.Transformations are preferably serialized (e.g., as XML) and stored asblobs in the database.

Plan processing can involve the following processes: Selection refers tothe process of selecting a plan to invoke, from problem data or otherinputs. Activation refers to the processes of instantiating a plan froman abstract plan, binding runtime parameters, checking prerequisites,making the plan deployment-specific, and building plan metadata.Rendering refers to depicting plans to the end-user in a way that allowsthe end-user to manage plans. Execution means executing a plan againstthe deployment 10. Finally, retirement means retiring plans that havecompleted, been skipped, failed, etc.

The GUI 29 can preferably inspect all plans at any stage in processingto provide transparency to plan processing to the end-user.

In a preferred embodiment (it being understood that alternative plandevelopment processes/steps are possible), plan development involves thefollowing steps: plan instantiation, binding plan parameters, evaluatingplan prerequisites, specializing the plan for the deployment 10, andconstructing “aggregate shadows” of the plan. These steps can beperformed by the planning module 42. These steps are now described.

The plan is instantiated from an abstract plan. Instantiation involvesgenerating a unique plan identification or ID. Next, the plan parametersare bound to problem attributes. Binding preferably uses name-matching.Each problem can have a list of name-value pairs that contain attributesof the problem, and each plan can have a list of named parameters. Forexample, if a problem has name-value pairs “host=foo” and“process_id=123,” the plan would have a list of named parameters “host”and “process_id.” The problems are preferably processed in the problemlist order. If the parameter names cannot be resolved by the problemattributes, or if type conversion fails, the plan is preferably retiredand an error is returned.

Then the prerequisites component of the plan object tree is preferablyevaluated. If the prerequisites are not met, the plan is preferablyretired with an appropriate resolution. For example, a specific planmight only be applicable if Microsoft Exchange SP2™ or earlier isinstalled. In traversing and evaluating the prerequisite component ofthe plan object tree, application model queries may need to beperformed, results tested, etc. If the prerequisites are not met, theplan can invoke a runtime interface (e.g., “Plan.PrerequisitesFailed”),in which a textual reason may be provided (this may be invoked multipletimes). The text is then aggregated for auditing. If prerequisites arenot met, the plan is retired with an error being returned.

Specializing the plan for the deployment 10 preferably involvestraversing the solution node of the object tree to identifydeployment-specific portions of the plan. For example, a specific planmay contain different solutions depending on the version of theapplication 10 that is installed. If specialization reduces the plan toan empty set (i.e., the plan has no steps), it is retired and an erroris returned.

A “shadow” is the set of components of the application model 24 thatsomething will affect. An “aggregate shadow” is the union of all partsin a plan, and contains all components affected by the execution of theplan. To evaluate the dependencies and effects of a plan, queries can beperformed by the plan. In addition, operators produce effects. Thisinformation is represented as shadows, and is used to determinepotential conflicts. If the effects of two plans intersect, the plansare potentially mutually exclusive and should not be executedconcurrently. If the effects of a plan intersect with the dependenciesof a best practice, the plan potentially conflicts with the bestpractice. This may cause the best practice to be triggered forevaluation after the plan is executed. Shadows represent AM propertycollections. They allow determining, for example, that a best practicedepends on the same property that a plan modifies. This is a hint thatthe plan may conflict with the best practice, but it does not determinethat such is true (e.g., the plan may modify the property within thebounds proscribed by the best practice).

As a plan object tree is traversed (e.g., by the automation subsystem 32or by a human administrator via the GUI 29), the automation subsystem 32preferably aggregates the rendering metadata from each node. Therendering metadata can be HTML. The GUI 29 can handle “dead branches”(i.e., object tree branches that are inoperable due to inputs receivedat decision factors of the tree, such as inputs received from the humanadministrator) by eliminating or identifying them (e.g., “graying out”).The method by which the GUI 29 treats dead branches can be based on userpreference.

Where variables are unresolved, plan rendering preferably comprisespresenting all possible paths. For example, suppose a plan fragmentreads as follows:

-   -   if (useWorkaround)        -   Operator.A( );    -   else        -   Operator.B( )            If the variable “useWorkaround” is found or resolved to be            true, then the GUI 29 preferably only renders Operator.A. On            the other hand, if “useWorkaround” is unresolved, then the            GUI 29 preferably renders the condition and both branches.            Unresolved variables can be rendered using their names (or            explicit metadata associated with them). For example,            consider the following plan fragment:    -   Operator.RestartService (server, “SMTP”)        If the variable “server” resolved to “NYC_PDC,” then this plan        fragment can be rendered as “Restart SMTP on NYC_PDC.” If        “server” were unresolved, it can be rendered as “Restart SMTP on        server.”

In a preferred embodiment, the automation subsystem 32 includes separate“evaluation” and “execution” modes for traversing a plan object tree.The mode affects how the interface nodes are processed. Evaluation modeis used during plan activation and rendering. In this mode, queryinterfaces and runtime interfaces are executed, but operator interfacesare only used to produce rendering and shadow metadata. In other words,when in evaluation mode, the plan is not executed against the deployment10. In execution mode, operators are invoked. Also, in execution mode,the queries can be re-invoked and the results can be compared againstthose obtained during evaluation.

Plan traversal produces context (i.e., variables are resolved, queriedinformation is obtained, etc.) that can be serialized with the plan.This allows plans to be queued, awaiting some action, and later dequeuedfor additional processing. For example, a rendering agent (which canreside in the automation subsystem 32 or elsewhere within themeta-application 20) may queue a plan that requires feedback from auser. When the user eventually provides the required feedback, the agentcan dequeue the plan, resolve the result variable of the feedbackinterface, and continue the plan.

Root Cause Analysis

In some situations and embodiments, it is possible for a problem to nothave an actionable remedy (either because the problem is not linked to aremedy or because all applicable remedies have failed to correct theproblem). Also, a partially triggered logic rule may in some casessuggest that something is potentially wrong with the deployment 10, buta remedy is not available until the rule is fully matched by ProblemLogic. Another possibility is that many problems, some with the sameseverity, might be triggered at once. In these cases, the analysissubsystem 30 can be configured to perform root cause analysis todetermine the actual cause of these problems (either automatically orwhen prompted by an administrator). The root cause analysis module 41(FIG. 1) is preferably configured to test appropriate components of thedeployment 10 to attempt to determine which component is the actual rootcause of the problem or set of problems, and which problems are causedby this problematic component.

Root cause analysis is the process of analyzing and testing variouscomponents of the deployment 10 to determine (1) which component isactually causing a problem, and (2) what other problems are caused bythe same misbehaving component. The root cause analysis module 41 caninclude algorithms that rely upon the application model 24. As explainedabove, the application model 24 preferably represents the variousobjects of the deployment 10, directed dependency relationships betweenthe objects, and a set of troubleshooting “unit tests” for each type ofobject. A unit test is a test of one specific feature or element offunctionality. For example, one particular unit test might send a simpleemail to assess whether a specific server is able to forward or storeemail messages.

As used herein, a “root cause” is specific physical data on a specificphysical machine, the data not being caused by any other specificphysical data on any machine. The curing of a root cause leadsexpeditiously to the cure of some or all extant abnormal conditions inthe deployed application managed by the meta-application 20. The rootcause analysis module 41 is preferably configured to iteratively usepattern recognition methods on the application model 24 and diagnosticunit tests to further isolate causes, including root causes, of problemsexisting in the application deployment 10 managed by themeta-application 20.

Value of Root Cause Analysis

The root cause analysis module 41 complements the Problem Logicalgorithm by (i) finding causes of problems when Problem Logic lacks theknowledge to find the causes more directly, and (ii) isolating the rootcauses of problems when Problem Logic finds no causes, finds too manycauses, or finds the wrong cause. Problem Logic is limited by theknowledge that is encoded into it (i.e., the knowledge in the knowledgebase 22). Root cause analysis can circumvent insufficient specificknowledge and add to what Problem Logic can do by diagnosing problemsusing general pattern recognition principles on the application model24. The root cause analysis module 41 partly fills in where ProblemLogic knowledge is missing and where Problem Logic can use additionalguidance.

If Problem Logic does not match any rules, but a problem exists, theroot cause analysis module 41 can preferably detect problems thatProblem Logic does not find by marking application model objectsassociated with partially triggered rules and applying root causeanalysis strategies.

If multiple Problem Logic rules trigger simultaneously, the root causeanalysis module 41 can preferably determine which problems are causingother problems. For example, in a meta-application 20 that manages adeployment 10 of Microsoft Exchange™, suppose the root cause analysismodule 41 uses causal link information stored in the application model24 to detect the following three problems: (1) SMTP service has stopped,(2) email has stopped, and (3) email is slow. Logically, the stoppage ofSMTP service has likely caused the stoppage of email, which is thelikely cause of the detection of slow email. If the root cause is thatSMTP service has stopped, remedies specific to the problem of slow emailare not worth trying until remedies for the stopped SMTP service aresuccessful. Therefore, the root cause analysis module's patternrecognition determination of root causes and diagnostic unit testing cannarrow sets of Problem Logic problems to be considered for immediateremedy execution and can prioritize remedies.

If a Problem Logic rule triggers, but Problem Logic does not offer anyremedies, the root cause analysis module 41 can preferably discovercurable root causes. The objects associated with the correspondingmatched problem can be marked on the application model 24 and the rootcause analysis module 41 can then identify and diagnose the causes ofthe deployment problem.

If a Problem Logic rule triggers, but an associated remedy fails to curethe problem, the root cause analysis module 41 can preferably discoverother possible remedies. FIGS. 23 and 24, for example, illustrate howroot cause analysis can implicate “bystander” problem objects in theapplication model 24, which Problem Logic may not have detected (FIGS.23 and 24 are described below). The root cause analysis module 41preferably conducts diagnostic unit tests and remedies on these objects,the unit tests and remedies being preferably stored in the applicationmodel 24 in association with the objects. Therefore, these root causeanalysis actions may solve problems that Problem Logic would give up on.

Causes and Root Causes

For a meta-application 20, one operationally useful definition of cause,suitable for investigation, requires that a cause be discoverable, arelatively permanent record (i.e., preferably not an extremelytransitory state or human participant), curable, and optionallytime-stamped. A timestamp can be precise (e.g., file creation date, logfile entry time, etc.), coarse (e.g., occurred after a prior Windows™registry backup time), or nonexistent.

A cause, in the context of a meta-application 20, typically comprisesspecific physical data on a specific physical machine. A cause might bea bad binary, setting, file, installation, or anomalous data. Lesscommon causes might be a service state (e.g., a service was neverstarted), performance limit, and resource limit. For example, in thecase of a meta-application 20 that manages a deployment 10 of MicrosoftExchange™, causes can arise from software bug/design, installation,permissions/security, other software, data peculiarity, networkingconfiguration, other configuration, Active Directory, service,Metabase/MSIE, Registry, performance limit, files, hardware, and virusesor worms.

A root cause is a main cause. This means, particularly, that a rootcause has no antecedent cause in any chain of causally linked causes. Ifa root cause is remedied, there is no reason for it to quickly reappear,because such a reason would be an upstream cause (i.e., upstream in thecausality chain). On the other hand, remedied ordinary causes couldreappear because upstream generating causes remain unremedied. A rootcause is not necessarily an original cause, for the reason that originalcauses often are not discoverable. What is desirable is that a rootcause be a main cause, which, if cured, leads expeditiously to the cureof a plurality (preferably all) of extant abnormal conditions in thedeployment 10 managed by the meta-application 20.

Root Cause Analysis Algorithm

This section describes a preferred algorithm conducted by the root causeanalysis module 41 to perform root cause analysis. As discussed above,the meta-application 20 preferably has an internalized description ofthe application deployment 10, referred to herein as the applicationmodel 24. A preferred approach to root cause analysis discerns rootcauses by examining the state of the application model 24. In apreferred embodiment, the application model 24 comprises a labeled,directed graph that includes representations of all significantdeployment objects that might be implicated or affected by a problem orset of problems, including causes and root causes. Classes of objectswithin the application model 24 can provide diagnostic unit tests andremedies as methods that can be applied to the actual objects in thedeployment 10, generally at some cost (e.g., time, space, risk,temporary loss of service, or required human assistance). Preferably,the objects in the application model 24 themselves provide history logs,dependencies, and causal links as data members.

The application model 24 provides a number of functionalities to themeta-application 20, preferably including (i) consistency, (ii) sharing,(iii) transparency, (iv) archival, and (v) database functionalities.With regard to consistency, the application model 24 preferably enforcesa consistent view among Problem Logic rules, such that the applicationmodel reduces the possibility of contradictory assumptions made by themeta-application 20. Also, the Problem Logic rules preferably “speak thesame language.” Regarding sharing, the application model 24 reducesduplication of deployment 10 information, by maintaining a centralized,dynamically updating repository of such information. With regard totransparency, the application model 24 provides a concentrated datastructure that permits easier understanding of the applicationdeployment 10, compared to more diffusely spread out proceduralknowledge. Other components of the meta-application 20 preferably havevisibility into the application model 24 and can traverse its datastructure. Regarding archival, the application model 24 can preferablybe backed up. Recordation of the history of the application deploymentstate can provide numerous benefits. Finally, powerful, unpredictablequeries can be run against the application model 24 as a database.

Thus, preferred root cause analysis algorithms use the application model24 as a tool to find causes and root causes. In the preferredembodiment, an approach to root cause analysis involves iterated patternrecognition within the application model 24 to identify potential causesand root causes, and applying diagnostic unit tests to further isolatecauses, including root causes, of problems existing in the deployment10. In this general approach, application model images of root causesare identifiable as characteristic substructures of the applicationmodel data structure. One particular root cause analysis algorithm isthe following:

Root Cause Analysis Algorithm:

while (true) {

-   -   Mark anomalous objects on the application model 24;    -   Use pattern-recognition to identify causes and candidate root        causes on the marked application model 24;    -   Apply diagnostic unit tests on candidate root cause objects;    -   Report or remedy root cause objects;

}

A root cause analysis algorithm, such as the one above, can be called asa subroutine by the overall orchestration module 21 of themeta-application 20. For example:

Orchestration Algorithm:

while (true) {

-   -   if (Problem Logic can do processing) {        -   Call Problem Logic;    -   } else if (Root Cause Analysis can do processing) {        -   Call Root Cause Analysis;    -   } else {        -   Other processing;    -   }

Since the Problem Logic algorithm provides very domain-specific andespecially effective knowledge for quickly remedying applicationdeployment problems, the orchestration module 21 preferably callsProblem Logic first when investigating anomalous events. In cases whereProblem Logic is unable to provide actionable information relating toproblems, the orchestration module 21 preferably calls a suitable rootcause analysis algorithm. Since the preferred root cause analysisalgorithm relies on very general pattern recognition, search, anddiagnostic unit testing, it is advantageously used when Problem Logic isunable to remedy a problem.

An initial step in the preferred root cause analysis algorithm is tomark anomalous objects on the application model 24. One method ofmarking anomalous objects involves identifying objects implicated byProblem Logic activities. For example, objects that are bound tovariables in either partially or completely triggered rules can bemarked. Another method of marking anomalous objects involves modeling.For example, mathematical modeling and baselining of deployment 10objects can identify anomalies even if no Problem Logic rules areactively operating on such objects. Skilled artisans will recognize thata variety of other methods can alternatively or additionally be used tomark anomalous objects of the application model 24. Marked objects aresometimes referred to herein as “problem objects” or “unhealthyobjects.”

After problem objects are “marked” on the application model 24, afollowing step of the preferred root cause analysis algorithm is to usepattern recognition to identify causes and candidate root causes on themarked application model. A variety of different strategies can beemployed to find causes and root causes. Some of these strategies arenow described. Skilled artisans will appreciate that the techniquesdescribed below are not exhaustive, and other approaches may beavailable.

One pattern-recognition technique, “configuration analysis,” looks forrecent property changes of marked objects of the application model 24. Arelated technique is to look for recent local configuration changes ofobjects that are “near” the marked objects. For example, FIG. 27 showsfour identical application model objects 220, 222, 224, and 226. Supposethe object 226 is marked as having a problem. Comparing theconfiguration of the problem object 226 to all three healthy objects220, 222, and 224, the standout dissimilarity is the small square 228 inthe lower right corner. This square 228 is filled in the problem object226 and unfilled in the healthy objects 220, 222, and 224. For example,the square 228 may represent a backed up mail queue or a disk space thatis over quota. Therefore, the square 228 can be identified as a rootcause candidate.

Another pattern-recognition technique, “cluster analysis,” involvesgrouping marked objects that are near each other in the applicationmodel 24 into clusters, such as by a k-means cluster analysis algorithm(k-means clustering is known in the art). Within a cluster, a primesuspect for a root cause candidate can be identified by suitable,plausible criteria, such as by considering causal links, dependencies,temporality, application model topology, and diagnostic unit tests.Appropriate cluster analysis dimensions include numerical measurementssuch as performance counters, math model statistics, link distance inthe application model 24, object similarity measures, and time. Furtherdetails concerning this “clustering” approach are disclosed in U.S.Provisional Patent Application No. 60/638,006, particularly on pages70-73 and Appendix A thereof.

Another pattern-recognition technique, “link analysis,” involvesinvestigating incriminating links or other information relating objectsin the application model 24. FIG. 23 illustrates an example, involvingunhealthy objects 260, 262, 264, and 266. The object 260 has directedlinks to the other three objects. Further, there are no unhealthyobjects that have directed links to the object 260 (in FIG. 23, thiscondition is represented by showing an unhealthy object with a directedlink in a dotted line to the object 260, and by showing an “X” on thedotted line). Since the object 260 points to other unhealthy objects,but has no unhealthy objects pointing to it, the object 260 ispreferably flagged a root cause candidate. FIG. 26 illustrates anotherexample, involving application model objects 230, 232, 234, 236, 238,and 240. In this example, an arrow extending from a first object to asecond object with a “d” label means that the first object depends onthe second object. For example, the first object may be a component ofthe second object, which means that the first object depends on thesecond object. Diagnostic unit tests can be applied to the applicationmodel objects in the “neighborhood” (i.e., nearby in the applicationmodel 24 representation of the deployment 10) of a detected problem.Suppose the objects 230 and 232 fail their unit tests (in FIGS. 23-26,the failure of a unit test is denoted by a darkened circle, and thepassing of a unit test is denoted by an unfilled circle), and theobjects 234, 236, 238, and 240 pass their unit tests. The failed object230 depends on the failed object 232. Since the failed object 232 doesnot depend on any other failed object, the object 232 is preferablyflagged as a root cause candidate.

Another pattern-recognition technique, “self comparison,” involvescomparing parts of the application model 24 to other parts of theapplication model. The differences between healthy parts and unhealthyparts that do not show up as differences between different healthy partsare identified as causes. For example, suppose a comparison between anunhealthy object and a healthy object reveals different IP addresses anddifferent DNS settings. Suppose also that a comparison between twohealthy objects reveals different IP addresses and the same DNS setting,which happens to be different than the DNS setting on the unhealthyobject. The IP address of the unhealthy object should not be considereda root cause candidate, because different healthy objects have differentIP addresses. However, the anomalous DNS setting of the unhealthy objectcan be flagged as a root cause candidate because different healthyobjects have the same DNS setting, which is different than the DNSsetting of the unhealthy object. FIG. 27 (discussed above) alsoillustrates this approach.

Another pattern-recognition technique, “temporal comparison,” is alsoexemplified by FIG. 27. This involves comparing the current state of theapplication model 24 and a previous state, to ascertain temporaldifferences.

Another pattern-recognition technique, “bystander analysis,” involvesinvestigating “bystander” objects. Ostensibly healthy objects (asdetermined, for example, by conducting successful unit tests) that areadjacent to or near a number of unhealthy objects are treated withsuspicion. If an ostensibly healthy object has a common type of link(not necessarily a dependency link) to all of the unhealthy objects, andif similar healthy objects are not linked to the unhealthy objects, thenthe first healthy object should be investigated. For example, FIG. 24shows a healthy object 242 having directed links to unhealthy objects244 and 246. Suppose that there are no unhealthy objects having directedlinks to the objects 244 and 246. In this case, the object 242 can beflagged as a root cause candidate because it is linked with multipleunhealthy objects that have no unhealthy objects linked to them. FIG. 25shows another example, involving ostensibly healthy objects 248, 252,254, and 258, and unhealthy objects 250 and 256. The object 248 hasdirected links to objects 250 and 256. The object 252 has directed linksto objects 250, 256, and 254. The object 258 has no links to the otherillustrated objects. Observe that multiple ostensibly healthy objects(objects 248 and 252) point to the same unhealthy objects 250 and 256.However, since the object 248 points only to unhealthy objects, it isthe preferred root cause candidate, in contrast to the object 252 thatpoints to both unhealthy and healthy objects.

Once pattern-recognition techniques are used to identify root causecandidates, a following step in the preferred root cause analysisalgorithm is to conduct increased diagnostics, troubleshooting, orremedies with respect to objects appearing in or intersecting with rootcause candidate structures. Diagnostic unit tests are preferably firstattempted on the root causes. If this does not resolve a problem, thendiagnostic unit tests are preferably applied on non-root causes. Theresults are preferably fed back into the application model 24. Forexample, test results of the diagnostic unit tests can be cached in thehistory logs of the application model objects to minimize duplicatetesting. Then, the root cause analysis algorithm loop is repeated. Thiscan be done in a well-founded way to guarantee termination if necessary.In other words, the algorithm can contain some criteria for stopping.However, it is also sufficient that the root cause analysis algorithmloop act as a perpetual ongoing process, provided that there issufficient guarantee that the algorithm can keep up with all the workthat is supplied to it (and which it may generate for itself).

Diagnostic unit tests for candidate root cause objects are provided asmethods of the application model object classes corresponding to thesuspect objects. The diagnostic unit tests can comprise diagnostictroubleshooting methodologies (as described above in the “EncodingDiagnostic Methodologies” subsection of the “Encoding Knowledge”section) or other appropriate specific diagnostic tests (e.g.,executables, tests provided by the maker of the managed application 10,meta-application shims, etc.) that provide useful output. The diagnosticunit tests preferably narrow down suspect object lists, drill down intocomponent objects, chase causes backwards, identify new suspect objectsto consider, etc. In addition to these approaches, diagnostic unit testscan possibly request additional telemetry that causes new featureinformation to be fed into Problem Logic for further consideration bythe meta-application 20.

Once these increased diagnostics, troubleshooting, or remedies areconducted with respect to the root cause candidate objects, a followingstep in the preferred root cause analysis algorithm is to report orremedy the root cause objects. Root cause analysis identifies root causeobjects in the application deployment 10 through inspection of themarked topology of the application model 24 and drill down unitdiagnostic testing of suspect candidate root cause objects.

Root cause analysis can lead to a positive outcome in several ways.First, identifying candidate root causes leads directly to thepossibility of the RCA module 41 applying problem object class remediesto the problem objects that have been identified as root causes. Second,the root cause analysis processing, through the diagnostic unit testing,may stimulate useful new feature information that will feed into ProblemLogic, trigger Problem Logic rules, and resolve problems by the ProblemLogic mechanism described above. Third, even if no remedy is found forsome problems, root cause analysis can nevertheless provide valuableinsight to a human administrator through the GUI 29. In such an “openloop,” the administrator and the meta-application 20 can cooperate tosemi-automatically diagnose and resolve problems by focusing on themenus of possible problem objects that the RCA module 41 reports.

Remedy outcomes (success or failure) can be stored in the history logsof the application model objects, to prevent repeated execution ofremedies that have already been attempted and also to influence futurerepairs of identical or similar problems. Likewise, aggregatestatistical information is propagated to static data members of theinvolved problem object classes.

An additional functional role for root cause analysis can be to furtherenhance the structured causality determination capabilities of ProblemLogic. As successes are found during this less structured augmentationto causality determination, the knowledge of the causality can beencoded, manually or automatically, back into Problem Logic. Further,statistics on application model objects related to root causality can betabulated for future reference by other modules and/or end users.

Encoding Knowledge

Encoding Goals

The Problem Logic encoding preferably includes encoding for logic rulesand an encoding format for predicates. The predicate information in theencoding is used for problem detection purposes, but may also includedata that is important for feature detection and implementing queries ofthe application model 24.

A preferred knowledge encoding methodology includes one or more of anumber of advantageous aspects, such as the following: The encoding ispreferably expressive enough to represent any possible, valid rule. Theencoding can preferably naturally represent metadata associated withrule components. The encoding is preferably extensible in abackward-compatible way, to avoid having to recode all the logic rulesif the encoding format is extended. The encoding preferably facilitateseasy validation (preferably directly in an editing tool used to createor modify the encoding), so that an encoder can analyze an encoded ruleor set of rules without actually running them through themeta-application 20 (e.g., spelling checks, basic sanity checks,predicate validity, rule triggerability, etc.). The encoding formatpreferably facilitates relatively easy encoding once the encoderunderstands the logic of a rule. In other words, the encoding should notrequire the encoder to prepare a complicated translation to the encodingformat—it should be “natural.” Also, predicates are preferablyrelatively easy to add (especially those that simply comprise queriesfor information about the deployment 10). Preferably, “super-encoders”can add predicates in a manner that allows other encoders to simply usethem. In a sense, this provides a macro-capability to create simplepredicates with complex underlying implementations that can be codedwithout the need to recompile the meta-application 20.

It will be understood that knowledge can be encoded from a large varietyof different types of knowledge sources, including knowledge basearticles, books, other text documents, information obtained from domainexperts, orally received knowledge, and the like.

Encoding Language Formats

The encoding can be done in any suitable language. Two possibleapproaches for encoding the symptom logic are a “prolog-like” format andan XML format. The prolog approach has the advantage that it is easierto translate from an abstract logical understanding of a rule to aprolog rule, but only for encoders familiar with prolog. A disadvantageof prolog is that it may require a custom language (i.e., an extensionof prolog) and custom tools to enter, edit, validate, and parse thelanguage.

The XML approach has the advantage that there is already a standard (XMLSchema) to describe significant parts of the Problem Logic rule XMLformat, and excellent pre-existing XML tools can be used to facilitateentry, editing, validation, and parsing. XML also allows for backwardlycompatible extension and for adding new data to any rule component. Apossible disadvantage of XML is that it takes some extra effort totranslate abstract logical understanding into the XML format, unless oneis very familiar with XML and the Problem Logic XML format. A hybridapproach would be to enter rules in a prolog-like language which is thentranslated to the XML format (in which it is easier to do normalediting, metadata editing, validation, and parsing).

In either approach, once the encoding is parsed, the output ispreferably an identical parse tree, and all downstream components of theencoded knowledge are preferably completely unaware of how the knowledgewas originally encoded.

Encoded knowledge, such as the knowledge stored in the knowledge base22, can come from a variety of sources. Two important sources ofknowledge are knowledge base articles and recommended diagnosticprocedures extracted from human experts. These types of knowledge can beencoded manually or automatically. Manual and automated encoding methodsare described below.

Encoding Process

The following is one possible procedure by which encoders can generatelogic rules from knowledge sources. This description is provided in thecontext of encoding knowledge derived from knowledge base articles, suchas Microsoft™ Knowledge Base articles. However, aspects of thisprocedure can also be used for encoding diagnostic methods, which aremore fully described in the next subsection of this application. Also,while the following description is provided in the context of using XMLas a programming language, it will be appreciated that other programminglanguages can be used. Skilled artisans will also understand that theencoding process can encompass additional or fewer steps than set forthbelow, and that the following represents only one embodiment. Some ofthe steps in this procedure can be partially or fully automated withinsoftware.

In a first step, the encoder preferably reads the knowledge base articleor other knowledge source text in order to understand the problem andhow it may be programmatically identified. This may entail identifyingapplication model objects and telemetry predicates (if any) associatedwith the article. The encoder may need to review a resolution section ofthe article to fully identify all the components required foridentification of the particular problem. The encoder may also need torun administrative tools that are referenced in the article (or relatedto things in the article) to learn about which objects of theapplication model 24 are involved, as well as the objects' relevantproperties.

In a next step, the encoder preferably identifies or generates a querythat will locate all relevant objects of the application model 24. Thisstep produces application model query predicates that can be encoded inthe rule. Some queries may be so common (in other Problem Logic rules)that there may already be a predicate created for it, which can be usedas a shortcut.

In a next step, if it is necessary to insert a telemetry predicate intothe rule, the encoder can find the correct predicate from a predicatelist in the XML Schema (see “Application Model” section above). Theencoder should check the argument types in the XML Schema of thepredicate to determine whether it has all the required application modelobjects. If not, then the encoder can use the application model objectsin hand to find the query that will obtain the other correct applicationmodel objects (through various relationships, such as parent-child,dependency, and others).

In a next step, the encoder preferably identifies the logic of the ruleand encodes the rule using all the predicates identified in previoussteps and the logical connectives described above, including but notlimited to AND, OR, and THEN.

In a next step, the encoder assigns “contribution” values to each of thepredicates of the rule. In one embodiment, predicates generally have acontribution of “very high” (or the like), meaning that the predicate isvery important and its absence/existence should significantlylower/increase the confidence that the rule is triggered (the exacteffect depends on the logic of the rule). However, there are someinstances in which a predicate is obviously less important, usuallybecause a knowledge base article uses language like “may” or “could beaffected by,” or the article is very vague about the importance of aparticular component. If the encoder is unclear about the role of apredicate in the rule, it is best to seek clarification from an expertassociated with the managed application 10. As explained above, thecontribution value can intuitively be thought of as a metric thatslightly modifies the behavior of an AND gate, so that a “minor” inputto the AND gate does not adversely affect the confidence of a rule (bymaking it too low) if the input is false. Similarly, if a minor input toan OR gate is true, in some cases it should be given a low contributionvalue so that it does not too greatly increase the confidence of a rule.

In a next step, the encoder assigns “need” values or attributes to eachpredicate, which indicate if the predicate is required for the logic ofthe rule. Intuitively, if a predicate's need value is “required,” then afalse predicate can “veto” an AND gate and set its output confidence tozero, even if other predicates have non-zero confidences. Conversely, ifa predicate has a high confidence and a need value of “required,” it can“favor” an OR gate even if the other predicates have zero confidence. Onthe other hand, if a predicate's need value is “optional,” then thepredicate is essentially not needed. If the optional predicate is falseand is an input to an AND gate, then the AND gate will not necessarilyhave a zero confidence. If an optional predicate is true and is an inputto an AND gate, then the AND gate will have a higher confidence. Forexample, suppose a rule has two telemetry predicates that must be truefor the rule to trigger. Suppose further that the rule includes apredicate describing a “user-generated event” that, if true, shouldincrease the rule's confidence, and that, if not true, should not affectthe rule's confidence. The desired result can be achieved by setting theneed value of the user-generated event to “optional.” By default,predicates should generally have need values of “required” andcontribution values of “very high,” which should be changed only whenthere is a clear need.

Once the rule is completely encoded, it can be validated against the XMLSchema, which should identify typographical errors and gross syntacticerrors. After XML validation, the rule can be validated for logic errors(malformed queries, incorrect triggering sequence, etc.). After thesevalidations, the encoded logic rule is ready to be inserted into theknowledge base 22 of the meta-application 20.

XML Encoding

As explained above, XML is a preferred encoding language for the logicrules in the knowledge base 22. In a preferred embodiment, the XMLencoding is split into two formats: an entry-optimized “authoring”format and a “native” format. The authoring format allows for the use ofmacros and shortcuts (like embedding simple child tags as attributes ona parent tag or defaulting entire sections of XML so that the encoderdoes not need to create them, unless the encoders wants to specializeit) to simplify the encoding and to make the encoding more brief. Theauthoring format provides a layer of abstraction above the native XMLthat can be changed independently of rules and can insulate rules fromstructural or best practices changes in rule encoding. The authoring XMLcan be transformed by XSLT into the native XML, and it is during thetransformation process that macros and shortcuts are transformed to themore verbose native format.

The native format is preferably optimized to express rules in the mostprecise way possible to simplify the meta-application's internalizationof the rules. The native format more closely resembles the structureneeded by Problem Logic. While the native format can be entered andedited by an encoder, in a preferred process the encoder uses theauthoring XML format. The encoder preferably very rarely works on theauthoring-to-native XSL transforms. Having a transparent look at theparse tree before it goes into the meta-application 20 should alsofacilitate debugging, since no “extra” transformations will be done inthe meta-application 20 and thus be a black box to encoders.

Thus, a preferred XML encoding process involves the steps describedbelow. Skilled artisans will understand that the XML encoding processcan encompass additional or fewer steps than set forth below, and thatthe following represents only one embodiment.

In a first step, encoders write the rule in authoring format, whichshould be a concise and easy format to use. Since an XML Schema thatdefines the authoring format exists, the XML entry tool can beconfigured to automatically validate the rule as it is authored. Theauthoring format is preferably specially built to allow the XML Schemato check as much of the validity of a rule as possible, so that new tagsare created for each predicate instead of having a single predicate tag.This allows the XML Schema to properly validate each predicateindividually.

In a next step, the authoring XML is transformed via XSLT into nativeformat. In this step, macros and shortcuts can be expanded. Anytransformation that is achievable by XSLT can help simplify authoringXML. XSL provides a convenient and relatively easy mechanism to helpsimplify authoring XML. For the lightweight macro-like activities ofthis stage, XSL should be sufficient, with the advantage that encoderscan use a simplified format that reduces errors on the authoring side.If XSLT does not provide enough functionality, then additional C++ codecan be provided to transform post-XSLT transformed authoring XML intonative XML.

In a next step, the native XML is fed into the meta-application 20,which internalizes the rule. Preferably, an XML Schema exists to allowthe meta-application 20 to validate the native XML at this stage. Then,in a next step, a command line tool can perform additional validationsof the rules. For example, the command line tool can verify that a rulehas a proper triggering chain, that the queries are well formed, etc.This tool can be used by encoders to ensure that the rule is optimallyformed.

Further guidance is provided by U.S. Provisional Patent Application No.60/638,006, which discloses, in Appendix B, (1) exemplary XML Schema andencoded logic rules, and (2) exemplary rule component tags forimplementing query predicates.

Encoding Diagnostic Methodologies

Some sources of knowledge about the managed application 10, such asknowledge base articles and other reference materials, tend to describeproblems in an ad hoc manner. For example, a knowledge base article isonly relevant if the particular features described in the article arecurrently present within the deployment 10. If the meta-application 20finds that a particular logical combination of conditions (i.e., a rule)exists, then the problem is matched and an associated remedy can beidentified. However, since knowledge base articles represent isolatedknowledge points, rules obtained from knowledge base articles often donot lend themselves to an intelligent organization or hierarchy withinProblem Logic. Another limitation of knowledge base articles is that,since they are generally issued by the maker of the software application10, they are typically not comprehensive. The software maker typicallyonly publishes knowledge base articles when enough customers submitquestions or complaints about certain problems. Thus, many types ofproblems are not described by knowledge base articles. Also, manyknowledge base articles are relevant only to specific versions of thesoftware, which may be superseded by a new version shortly after theknowledge base article is released.

These limitations can be substantially overcome by encoding diagnostictroubleshooting methods that human experts would use when confrontedwith one or more anomalous features or problems with the deployment 10.Accordingly, a preferred embodiment of the meta-application 20 employsdiagnostic methods that are encoded as rules within the knowledge base22 and then used by Problem Logic to detect problems within thedeployment 10. One embodiment involves constructing separate diagnosticmethods that each focus (either exclusively or non-exclusively) on oneof the components of the application model 24. This approach offers amore coherent and natural way to detect problems, and it lends itself toa substantially more intelligent organization or hierarchy of ruleswithin Problem Logic. Skilled artisans will appreciate that encodeddiagnostic methods can be utilized in addition to other forms ofknowledge, such as knowledge base articles, best practices, and thelike.

A preferred method of encoding diagnostic troubleshooting methodologiesinvolves creating troubleshooting decision trees in the form ofcomputer-implemented flow charts, and then using a tool toprogrammatically convert the flow charts into encoded knowledge that canbe used by the meta-application 20. The following describes a method inaccordance with one embodiment.

In a first step, one or more individuals with a high level of expertiseabout an application 10 to be managed by the meta-application 20(“troubleshooting experts”) create the knowledge to be leveraged. Rulesor troubleshooting methodologies are preferably diagrammaticallyspecified in a flowchart-like structure, such that the rules are made upof a network of “decision factors” that have “yes” and “no” paths.Compared to an encoded form (e.g., XML), this diagrammaticrepresentation of the diagnostic method is much more intuitive and easyto review, understand, and check for correctness. In one embodiment, atool like Visio™ is used with customized plugins to facilitate theknowledge creation and encoding. In this context, each rule is adifferent navigation of a series of decision factors (i.e., a differentcombination of yes or no paths following decision factors), ending in aset of remedies/plans. The troubleshooting expert(s) can create separatetrees of rules, such that each tree substantially covers one of aplurality of preferably non-overlapping “critical components” of theapplication model 24. In some embodiments, decision factors can beshared among trees. Also, in some embodiments decision factors can bespecified at a high level for each tree creation step. Troubleshootingexperts can use these “high-level decision factors,” even if they werecreated by other troubleshooting experts, to produce a low-levelspecification of the decision factor, which can be encoded by aknowledge engineer who does not have full expertise about theapplication 10 (see next paragraph). The low-level specificationpreferably takes into account the inputs and outputs required for eachdecision factor in a tree, so that the set of decision factors for atree will be consistent. In this context, a high-level decision factorcomprises a broad, high-level statement of the decision factor, suitablefor human consumption.

FIG. 41 shows an example of a high-level flowchart that describes adiagnostic troubleshooting method for troubleshooting a component (e.g.,a set of related objects) of an application model 24 for a deployment 10of Microsoft Exchange™. The illustrated flowchart includes decisionfactors having “yes” and “no” paths. Those of ordinary skill in the artwill appreciate that flowcharts such the one shown in FIG. 41 can beprovided for a plurality of different objects or groups of objects ofthe application model 24. Preferably, enough flowcharts like that shownin FIG. 41 are provided so that every object in the application model 24can be diagnosed or troubleshot by at least one of the flowcharts. Suchflowcharts will typically differ depending upon the specific application10 that is managed. FIG. 42 shows a portion of the flowchart of FIG. 41,magnified for ease of understanding.

A next step of the method comprises an intermediate encoding step,wherein the trees or flowcharts are optimized. Knowledge engineerswithout advanced expertise about the application 10 begin encoding thedecision factors simultaneously using a suitable encoding language,thereby producing “low-level decision factors.” Decision factor encodingcan be reviewed by encoding experts to ensure quality. Actualimplementation information, including additional inputs and outputs, maybe required to produce valid rules (i.e., rules that are usable byProblem Logic), and encoders can optimize the decision factors byincreasing the sharing of common data. These low-level decision factorsmay comprise encoded rule-fragments that may apply to various logicrules. However, each low-level decision factor is preferably encodedonly once, and then a rule generation tool (see next paragraph)preferably plugs them into the various rules as required, or provideslinks/references from rules to encoded rule-fragments as necessary foreach rule. In this manner, a meta-application 20 can contain anupdatable library of low-level decision factors that are available foruse as needed by various rules. The encoders can modify the knowledgeflowchart (e.g., the Visio™ diagram) by inserting decision factoroptimization information. In a typical scenario, each tree is owned byone knowledge engineer who does this. However, the approach preferablyallows any given decision factor to be worked on by many knowledgeengineers.

In a next step, the knowledge rules are generated. Once all the decisionfactors are encoded and reviewed, a “rule generation tool” canprogrammatically convert each of the computer-implemented knowledgetrees (described above) and the encoded decision factors into a set ofrules that completely implement the tree in an encoding language orformat that can be used by the meta-application 20. The rule generationtool can have one or more of a variety of additional differentfunctionalities, such as the following: First, since the tree representsknowledge at a high level, the rule generation tool can preferablyverify knowledge consistency at a high level. Second, the tool canpreferably automatically produce user-readable explanations of each rulebased on the tree diagram and metadata in the decision factors. Third,the knowledge trees and the encoded decision factors preferably providethe rule generation tool with enough context to automatically performmany encoding tasks that would otherwise have to be done manually.Fourth, the tool can preferably automatically optimize rule encodingbased on the known performance characteristics of the system. Forexample, the tool can be configured to merge decision factors to improveperformance. Normally, this would involve the collaboration of multipleencoders, but the tool can perform the merging itself and thereby allowthe encoders to work independently and more quickly. Fifth, the tool canpreferably automatically produce rule metadata that can be used bydownstream modules (e.g., the problem detector 38) to analyze the rules.In this regard, the tool can preferably specify all the decision factorsat a high level so that the root cause analysis module 41 can determineif rules that the meta-application 20 matches are related to each otherat a high level. Sixth, the rule can preferably automatically producetest plans and test data to make sure that the meta-application 20 canproperly process the encoded knowledge. Once all the rules aregenerated, they can be used by the meta-application 20.

This approach offers a number of advantages. Encoding work can bedivided into a number of stages that can be worked on by multiple peoplesimultaneously. Logic decisions are made by troubleshooting experts, whoproduce an unambiguous tree (e.g., a Visio™ diagram) that can be moreefficiently and intuitively analyzed and discussed. The rule generationtool can provide multiple functionalities, as discussed above, toimprove the speed and quality of knowledge encoding. Encoding tasks thatrequire global visibility are automated, which allows knowledgeengineers to work on small self-contained tasks that can be more easilyreviewed.

User Interface

As explained above, the meta-application 20 includes a user interface 29(FIG. 1), which is preferably a graphical user interface (GUI). Asexplained above, the GUI 29 provides information to one or more humanadministrators of the meta-application 20. Such information cancomprise, without limitation, a snapshot or overview of the deployment10 (e.g., servers, processes, etc.), application model discoveryprocesses, current status of deployment servers 12 (e.g., whether theservers 12 are healthy or problematic), detected features, detectedproblems, predicted future problems (so that the administrator can takesome corrective action before the problem manifests itself), recommendedcorrective actions, currently active plans (including plan objecttrees), reports on the success or failure of plans, detectedroot-causes, and the like. The user interface 29 of the meta-application20 can also or alternatively involve alerting administrators aboutrelevant events through email messages or other notification methods.The user interface 29 can also be accessible over the Internet, such asby a web browser.

The meta-application 20 can be configured to leverage the output ofother third party applications or operating systems that includefunctionality for monitoring the software application 10 (hereinreferred to as “third party monitoring tools”). For example, the GUI 29can be designed to work seamlessly with MOM (Microsoft OperationsManager™). Thus, the meta-application 20 can function in two modes:“standalone mode” (without leveraging other monitoring applications) and“leveraging mode.” In standalone mode, the meta-application 20 functionssubstantially as described above.

In a preferred embodiment of the leveraging mode, much of themeta-application 20 functions exactly as it would in standalone mode.The meta-application 20 collects telemetry from servers 12 across thenetwork and evaluates the telemetry using feature detection algorithmsand logic rules in the knowledge base 22, in order to determine problemsand remedies. However, third party monitoring tools can add someadditional dimensions to the solution. For example, MOM™ can act as asource of alerts related to Microsoft Exchange™. Through the Exchange™management pack, MOM™ can determine problems that Exchange™ may beexperiencing, primarily through event log notifications which can thenbe read by the meta-application 20. When a third party monitoring toolgenerates a new alert, the meta-application 20 can log a correspondingevent (e.g., a feature) in the telemetry database 26, which can then beprocessed in the same way it would be if the meta-application were instandalone mode. Also, the meta-application 20 can use a third partymonitoring tool's alerting capabilities to augment basic alertingprovided by the meta-application 20 (e.g., email-based alerting). Forexample, MOM™ can send alerts to various devices, such as pagers, webservices, and the like.

In embodiments of the leveraging mode, the meta-application 20 cansynchronize its event state management with that of a third partymonitoring tool. For example, as events in MOM™ are marked as“assigned,” “acknowledged,” or “closed,” that state can be automaticallyreplicated or reflected in the meta-application 20. Similarly, when achange is made to an event in the meta-application 20, that state changecan be replicated in a third party monitoring tool. This allows IT usersto work in the application of their preference, and have the relevantevent state always present.

FIG. 20 shows a GUI screen display of one embodiment of ameta-application 20, which manages a deployment 10 of MicrosoftExchange™. The screen conveys various types of information about thedeployment 10. The “Environment” pane of the display screen illustratesthe components of the deployment 10, as represented within theapplication model 24. The “Server Status” and “Alarm Status” boxesdisplay summary information about problems (referred to in the screendisplay as “Root Causes”) that exist or have recently been detected.More detailed information about specific problems is displayed in the“Root Cause” pane.

The “Resolution” pane shows a flow diagram of a particular plan that iscurrently being executed, with each block in the flow diagramcorresponding to one step in the plan. The highlighted block representsthe step currently being performed. In the illustrated display screen,the highlighted block states “Please enter a working dns ip address.”The step currently being performed is described in the “Current Step”pane. In this example, the current step prompts the user of themeta-application 20 to enter a working DNS IP address, and the user'sresponse to this inquiry dictates the next plan step that will beexecuted. Some steps within the plan are action steps that, if executed,cause a change in the state of the deployment 10.

Typically, the user of the meta-application 20 is provided withinstructions for executing each action step via the GUI 29, or is giventhe option to specify whether the meta-application 20 should executeeach such action step. The meta-application 20 can describe actionstaken as the result of such action steps in an “Actions Taken” pane, andcan also record them in a persistent log.

As shown in the screen display of FIG. 21, the GUI 29 can providedetailed information related to detected problems in a “CorrelatedSymptoms” pane. The GUI 29 can also provide an option for the user toview a knowledge source, such as a knowledge base article, associatedwith a problem that has been detected.

EXAMPLE

This section describes an example in which a meta-application 20 usesencoded information extracted from a knowledge base article to diagnoseand remedy a particular problem in a deployment 10 of MicrosoftExchange™. FIGS. 22A and 22B together show Microsoft™ Knowledge BaseArticle ID No. 815759. This particular article describes a problem inwhich public folder hierarchy messages are stuck in outgoing queues inan Exchange™ 2000 server. The article identifies, under the “SYMPTOMS”heading, two particular warning or information messages that may belogged in the application log. The articles also indicates, under the“CAUSE” heading, that the issue may occur when the “Everyone” group isexplicitly denied permissions on both of two listed objects.

The knowledge base 22 of the meta-application 20 includes a logic rulethat describes this problem. The rule includes two inexpensive featurepredicates corresponding to the warning log messages, two inexpensivefeature predicates describing the denied permissions of the “Everyone”group on the two listed objects, and one more expensive predicatecomprising a “unit test” that tests whether email messages can be sentto public folders. The rule's specific logical combination of thesepredicates depending upon the relationships of the predicates to theproblem. However, for simplicity suppose that the rule requires all fivepredicates to be true (e.g., all five predicates are inputs to an ANDgate).

The Problem Detector 38 hosts various analysis algorithms, one of whichis Problem Logic. Problem Logic has loaded the rule associated with theknowledge base article in FIGS. 22A-B. Once the rule is loaded, ProblemLogic analyzes the rule and determines that, in order to evaluate therule for the given deployment 10, multiple feature detectors need to bestarted (using the procedure detailed above). Accordingly, Problem Logicinitiates these feature detectors, which then notify the appropriatemonitors 14 to look for the events and other features of the rule.

For purposes of this example, assume that, in a deployment 10 managed bythe meta-application 20, the permissions on the public folder aremisconfigured, causing the problem described in the article. As aresult, the managed application 10 registers the two warning messages inthe Exchange™ application log. These new log entries and picked up by amonitor 14 (FIG. 1) and sent to the meta-application 20 server 60 (FIG.3) as telemetry. The telemetry data becomes stored in the telemetrydatabase 26, and the feature detector 36 interprets the two error logentries as features. So two new “event” features are generated with thecorrect “event IDs” and other appropriate error information.

Problem Logic then receives these two new “event” features and, foreach, uses a discrimination network to identify and select all the ruleswithin the knowledge base 22 that contain an “event” feature predicatewith the matching “event ID.” One of the identified rules is the rulefor the illustrated article. The identified Problem Logic rule(s) thatcontain these feature predicates react to the fact that these newfeatures have arrived. The Problem Logic beads are advanced andappropriate variables are bound. Now, the other predicates in theidentified Problem Logic rules are activated, which means that the two“denied permissions” feature predicates in the rule for the illustratedarticle are activated.

In this case, the permissions on the public folder are verified as beingincorrect, as described in the article. Thus, two new features(corresponding to the “denied permissions predicates) are generated andthe discrimination network identifies problem logic rules to update.Once again, the problem logic beads are advanced and more variables arebound. Now, in the rule for the illustrated article, the final and moreexpensive feature predicate is activated. This predicate causes themeta-application 20 to perform a “unit test” to verify that emailmessages cannot be successfully sent to public folders (i.e., themeta-application tries to send a message).

After some time, the final feature predicate triggers. This causesanother feature to be generated and passed to Problem Logic. Then thediscrimination network identifies Problem Logic rules to update. At thispoint, the rule for the illustrated article has been matched because allfive feature predicates have become “true.” Thus, Problem Logicgenerates a corresponding problem.

If this problem appears alone, it is sent directly to the remedyselector 40. The remedy selector 40 may need to “lock” aspects of thedeployment 10 to prevent them from interfering with the resolution ofthis problem. The remedy selector 40 selects an abstract remedyassociated with this problem, and then the planning module 42instantiates and creates a deployment-specific plan designed to resolvethis problem (the remedies and plans are stored as metadata associatedwith the rule). If this problem appears together with other problems orthis problem does not have an associated remedy, the meta-application 20may activate the root cause analysis module 41 to determine whichproblems are caused by the same underlying root causes.

The knowledge base article shown in FIGS. 22A-B specifies a resolutioninvolving changing certain Active Directory (AD) settings for the“Everyone” user account. To do this, a plan takes one argument whosevalue was set during Problem Logic evaluation. In this case, theargument is the object of the application model 24 that represents theserver that cannot send messages to the public folder server. The logicrules contains metadata necessary to render and execute the plan, suchas information used to organize the order of the plans, the argumentsrequired to correctly execute each plan, query elements for obtainingnecessary information from the application model 24, and/or the actualplan steps.

After a remedy is selected, the planning module 42 constructs a planincluding three strings: the name of the AD organization, the name ofthe AD administrative group, and the name of the AD node that containsthe AD objects that need to be fixed. Next, a simple informational modelis created for the sub-plans. Finally, the two sub-plans are called toactually change the user permissions on the problematic objects.

The GUI 29 renders the plan for presentation to a human administrator,and the administrator can execute the plan. Alternatively, the executionengine 44 can automatically execute the plan on the administrator'sbehalf. While the plan is executed, the analysis subsystem 30 keepsactive the feature predicates of the logic rule used to match thisproblem, in order to be able to determine when/if the problem getscured. When all of the features that caused this problem become inactive(no longer are triggered), the problem expires and is consideredresolved. If the features remain triggered, this plan is optionally“reversed” and the next possible solution plan is executed. If allpossible plans are exhausted, then this fact is reported to the systemadministrator and he/she notifies the meta-application 20 if/when theproblem is ever corrected.

As discussed above, if a problem appears together with other problems ora problem does not have an associated remedy, the root cause analysis(RCA) module 41 may be activated to determine which of the problems arecaused by the same underlying root causes. The meta-application 20 canthen recommend that the problems be addressed in order of causality,and/or can dynamically create a plan to heal the root cause. In thisexample, mail messages bound for public folders cannot be sent, whichcauses the outbound message queues to grow steadily as more and moremessages bound for a public folder accumulate. This can impactperformance and trigger other types of problems that are actually causedby the problem described in the illustrated knowledge base article.

Suppose that the above-described clustering pattern recognition approachis used for root cause analysis. In this example, the RCA module 41groups several other problems together with the problem described in theillustrated knowledge base article. For example, other problems thatmight potentially appear include those related to excessive storagemedia use related to growing queues, and/or related to excessive CPUusage as attempts are constantly being made to empty the queuesunsuccessfully. The RCA module 41 creates a multidimensional space inwhich the problems are plotted, in which the dimensions of the spacerepresent aspects such as independent functional flows, connectivity,frequency of connectivity access, uniqueness of identity, time passage,dependence, statistical confidence, and the like. The above-describedclustering analysis (e.g., k-means clustering) is then performed.

In this case, the axes in the generated multidimensional space includean axis marked with redundant Exchange™ servers, an axis capturing thevarious components of the Exchange™ application (including the outboundmessage queue), and an axis representing the physical components of thecomputer (such as disk and CPU). The RCA module 41 finds that the rootproblem addressed in this flow and its derivatively caused problems havecoordinates close to one another along these axes and identicalcoordinates along other axes in the space irrelevant to them. Theseproblems are clustered together for further analysis. By analyzing thecommon attributes of the clustered problems (e.g., common applicationmodel components, temporal closeness or earliness, closeness orearliness in functional or data flows, and/or physical/containmentcloseness), the RCA module identifies two possibilities for theroot-cause candidate: the root public folder object (the object withincorrect permissions causing this problem), or the outbound messagequeues on some of the Exchange™ servers.

The RCA module 41 first considers an outbound message queue object asthe root-cause candidate, and tests the objects upon which the outboundmessage queue object depends. These objects are the network interface ofthe server and the inbound message queue object of the public folderserver. The meta-application 20 conducts unit tests for the outboundmessage queue and the inbound message queue. Suppose both unit testsfail. The RCA module 41 then considers the inbound message queue objectas the root-cause candidate and tests the objects upon which the inboundmessage queue depends. One of these objects is the public folder object.Suppose the public folder's unit test fails. The RCA module 41 nowconsiders the public folder object as the root-cause candidate. Finally,the RCA module 41 tests the objects upon which the public folder objectdepends. In this example, suppose all of the unit tests for theseobjects pass. The RCA module 41 then identifies the public folder objectas the component at the root cause of the identified problems. At thispoint, the meta-application 20 reports the groupings of problems,associated root-cause candidate objects, and unit test results to theadministrator, so that the administrator can take an appropriate action.

Although a meta-application has been disclosed in the context of certainembodiments and examples, it will be understood by those skilled in theart that the invention extends beyond the specifically disclosedembodiments to other alternative embodiments and/or uses and obviousmodifications and equivalents thereof. Further, as will be recognizedfrom the foregoing, the disclosed meta-application embodies a multitudeof distinct inventions, many of which can be practiced separately andindependently of others. Accordingly, the invention is not intended tobe limited by the specific disclosures of preferred embodiments herein.

1. A computer-implemented meta-application system for monitoring andanalyzing the operation of a deployment of a software application,comprising: a computer system comprising one or more computers, saidcomputer system programmed to implement at least: a monitoring componentthat collects data values of each of a plurality of state metricsassociated with the deployment of the software application; a repositorythat stores a plurality of rules, at least some of which map respectivecombinations of states associated with the state metrics tocorresponding problems; and an analysis engine that programmaticallydetects instances of said problems, at least in-part, by using the rulesto analyze the state metric data values collected by the monitoringcomponent; wherein at least one of the rules is configured to be used bythe analysis engine to generate a virtual circuit comprising: aplurality of atomic gates each configured to be used by the analysisengine to test for whether collected data values for one or more of thestate metrics indicate the existence of one of a plurality of possibleconditions of the deployment of the software application, and to producean output bead if the condition exists within the deployment; and aplurality of operator gates each having one or more inputs, each of theinputs configured to receive output beads from one of the atomic gatesor from another one of the operator gates, each operator gate configuredto be used by the analysis engine to test for a condition associatedwith received beads and to produce an output bead if the condition ismet; wherein the rule is configured to be applied by the analysis engineto automatically detect the existence of a problem within the deploymentbased on output beads generated from use of the operator gates.
 2. Themeta-application system of claim 1, wherein each of the atomic gatescomprises an open atomic formula comprising a predicate signature andone or more arguments, each argument comprising one of an unboundvariable and a constant term, each predicate signature and atomicformula corresponding to one of the possible conditions of thedeployment of the software application.
 3. The meta-application systemof claim 2, wherein the analysis engine is adapted to compare the openatomic formula of each atomic gate to a closed atomic formula comprisinga predicate signature and one or more arguments, each argument of theclosed atomic formula being a constant term, each closed atomic formulaindicative of a current condition of the deployment; wherein a matchbetween an open atomic formula of an atomic gate and a closed atomicformula that is compared to the open atomic formula implies: that apredicate signature of the closed atomic formula matches a predicatesignature of the open atomic formula; that a total number of argumentsof the closed atomic formula matches a total number of arguments of theopen atomic formula; that all of the constant term arguments of theclosed atomic formula match corresponding constant term arguments of theopen atomic formula; and that a deployment component associated with atleast one argument of the closed atomic formula meets the possiblecondition associated with the atomic gate; wherein the analysis engineis configured to respond to a match between the open atomic formula ofthe atomic gate and a received closed atomic formula by producing abead, the bead including variable bindings comprising assignments ofconstant term arguments of the closed atomic formula to correspondingunbound variables of the open atomic formula, the analysis engineconfigured to send the bead to an input of one of the operator gates. 4.The meta-application system of claim 3, wherein each constant term ofthe closed atomic formula comprises one of a numerical value and astring.
 5. The meta-application system of claim 3, wherein one of theoperator gates has a first input that receives output beads from a firstatomic gate, and a second input that receives output beads from a secondatomic gate, the first atomic gate having a first open atomic formulawith a particular unbound variable argument, the second atomic gatehaving a second open atomic formula also with said particular unboundvariable argument, said analysis engine configured to use said oneoperator gate to generate an output bead only if a constant termargument of a first closed atomic formula received by the first atomicgate matches a constant term argument of a second closed atomic formulareceived by the second atomic gate, wherein said constant term argumentof the first closed atomic formula corresponds to said particularunbound variable argument in the first open atomic formula, and saidconstant term argument of the second closed atomic formula correspondsto said particular unbound variable argument in the second open atomicformula.
 6. The meta-application system of claim 1, wherein at least oneof the operator gates is adapted to be used by the analysis engine togenerate an output bead only if a temporal measure associated with afirst bead received by the operator gate precedes a temporal measureassociated with a second bead received by the operator gate.
 7. Themeta-application system of claim 1, wherein at least one of the operatorgates is adapted to be used by the analysis engine to generate an outputbead only if an input bead is received on each of the operator gate'sinputs.
 8. The meta-application system of claim 1, wherein at least oneof the operator gates is adapted to be used by the analysis engine togenerate an output bead if an input bead is received on any of theoperator gate's inputs.
 9. The meta-application system of claim 1,wherein said at least one of the rules comprises an abstract remedy fortreating the problem described by the rule, the remedy comprising a setof one or more plans, each plan comprising steps and decision factorsfor correcting the problem, each plan comprising parameters, the systemfurther comprising an automation subsystem configured to determinebindings for the parameters based on satisfaction of the conditions ofthe rule.
 10. The meta-application system of claim 9, wherein theautomation subsystem includes a planning module configured to converteach plan into a tree of nodes comprising said steps and decisionfactors for correcting the problem.
 11. The meta-application system ofclaim 10, wherein at least one of the nodes comprises a scope nodecontaining one or more of (1) said bindings for the parameters of theplan, (2) metadata about the problem that the plan addresses, and (3) alogical formula of conditions corresponding to the problem.
 12. Themeta-application system of claim 10, wherein at least one of the nodescomprises an interface node configured to query for information neededto customize the plan to the deployment.
 13. The meta-application systemof claim 12, wherein the interface node is configured to solicit inputfrom a human user of the system.
 14. The meta-application system ofclaim 12, wherein the interface node is configured to query forinformation from a computer-implemented application model of thedeployment, the application model comprising: a representation of aplurality of hardware and software entities of the deployment; and arepresentation of dependencies between the entities.
 15. Themeta-application system of claim 10, wherein at least one of the nodescomprises an interface node configured to execute an action against thedeployment.
 16. The meta-application system of claim 9, wherein theautomation subsystem includes an execution engine configured to at leastpartially automate the execution of the plan against the deployment,based on the bindings for the parameters.
 17. The meta-applicationsystem of claim 16, wherein the automation subsystem detects and logsoutcomes of plans that are executed at least partially by the executionengine.
 18. The meta-application system of claim 9, wherein each of therules includes a numerical severity representing a degree to which theproblem associated with the rule adversely impacts the deployment, theautomation subsystem being configured to optimize an order of executionof a set of remedies associated with problems detected by the analysisengine, based on the severities of the rules associated with thedetected problems.
 19. The meta-application system of claim 1, whereinat least one of the operator gates specifies contribution weights forits inputs and has a first input with a first contribution weight and asecond input with a second contribution weight that is less than thefirst contribution weight, the analysis engine being adapted to givemore weight to the first input than to the second input for purposes ofproducing an output bead from the operator gate.
 20. Themeta-application system of claim 1, wherein at least one of the operatorgates specifies contribution weights for its inputs and has a firstinput with a first contribution weight and a second input with a secondcontribution weight that is less than the first contribution weight, theanalysis engine being adapted to give more weight to the first inputthan to the second input for purposes of producing a confidence valuerepresenting a degree of confidence that the deployment meets all of theconditions for which the operator gate tests.
 21. The meta-applicationsystem of claim 20, wherein the analysis engine is adapted to give moreweight to the first input than to the second input for purposes ofproducing a confidence value representing a degree of confidence thatthe problem associated with said at least one of the rules exists withinthe deployment.
 22. The meta-application system of claim 1, wherein theanalysis engine, in applying said at least one of the rules to thedeployment, is configured to receive a condition confidence valuerepresenting a confidence that a particular condition exists, and to usesaid condition confidence value to evaluate a confidence that theparticular problem described by the rule exists, wherein the tested-forconditions of the gates of the rule include static significance valuesindicative of the importance of the different conditions, the analysisengine configured to use the significance values to decline to reportthe problem when (1) one or more of the tested-for conditions are foundto be true, (2) the true conditions indicate that the problem iscurrently present in the deployment, and (3) a condition confidencevalue of at least one of the true conditions does not exceed thesignificance value of that particular condition.
 23. Themeta-application system of claim 1, wherein at least one of the operatorgates designates at least one of its inputs as a required input, anddesignates at least another one of its inputs as an optional input, suchthat the analysis engine, in using the operator gate, requires that therequired input receive a bead for the operator gate to be used toproduce an output bead, and such that the analysis engine does notrequire that the optional input receive a bead for the operator gate tobe used to produce an output bead.
 24. The meta-application system ofclaim 23, wherein said at least one of the operator gates is adapted tocause the system to query the deployment for data corresponding to therequired input before querying the deployment for data corresponding tothe optional input.
 25. The meta-application system of claim 23, whereinsaid at least one of the operator gates includes a confidencecalculation procedure for calculating a confidence value representing adegree of confidence that the deployment meets all of the conditions forwhich the operator gate tests, the confidence calculation procedureconfigured to produce a greater confidence value if the optional inputreceives a bead than if the optional input does not receive a bead. 26.The meta-application system of claim 25, wherein the analysis engine isconfigured to use the calculated confidence value in calculating aconfidence value in the existence of the problem associated with therule containing the operator gate.
 27. The meta-application system ofclaim 23, wherein said at least one of the operator gates includes aconfidence calculation procedure for calculating a confidence valuerepresenting a degree of confidence that the deployment meets all of theconditions for which the operator gate tests, the confidence calculationprocedure configured to compute a non-zero confidence value only if therequired input receives a bead.
 28. The meta-application system of claim27, wherein the analysis engine is configured to use the calculatedconfidence value in calculating a confidence value in the existence ofthe problem associated with the rule containing the operator gate. 29.The meta-application system of claim 1, further comprising acomputer-implemented application model of the deployment, theapplication model comprising: a representation of a plurality ofhardware and software entities of the deployment; and a representationof dependencies between the entities.
 30. The meta-application system ofclaim 29, wherein the application model is stored in an SQL databasethat supports SQL queries.
 31. The meta-application system of claim 29,wherein at least one of the gates is configured to cause the analysisengine to query the application model for specific deployment state datato be used by the analysis engine in determining whether to produce anoutput bead from the operator gate.
 32. The meta-application system ofclaim 29, wherein the analysis engine is configured to use said at leastone of the rules to produce identifications of entities of theapplication model that cause or are affected by the problem described bythe rule.
 33. The meta-application system of claim 29, furthercomprising a root cause analysis module configured to usepattern-matching to correlate a detected problem with one of theentities of the application model.
 34. The meta-application system ofclaim 29, wherein at least one of the rules comprises an encodeddiagnostic troubleshooting method associated with entities of theapplication model.
 35. The meta-application system of claim 29, whereinsaid at least one of the rules comprises an abstract remedy for treatingthe problem described by the rule, the remedy comprising a set of one ormore plans, each plan comprising steps and decision factors forcorrecting the problem, each plan comprising one or more parameters, thesystem further comprising an automation subsystem configured todetermine bindings for the one or more parameters based on satisfactionof the conditions of the rule; wherein the automation subsystem isconfigured to analyze the application model in order to evaluate whethera plan is suitable for executing on the deployment.
 36. Themeta-application system of claim 29, wherein said at least one of therules comprises an abstract remedy for treating the problem described bythe rule, the remedy comprising a set of one or more plans, each plancomprising steps and decision factors for correcting the problem, eachplan comprising one or more parameters, the system further comprising anautomation subsystem configured to determine bindings for the one ormore parameters based on satisfaction of the conditions of the rule;wherein the automation subsystem is configured to customize a plan basedon information obtained from the application model.
 37. Themeta-application system of claim 1, wherein a first of the operatorgates comprises a confidence calculation formula that differs from aconfidence calculation formula of a second operator gate having the samenumber of inputs, the analysis engine configured to apply the confidencecalculation formula of the first operator gate to at least one of thefirst operator gate's inputs for purposes of producing a confidencevalue associated with an output bead of the first operator gate.
 38. Themeta-application system of claim 37, wherein the confidence calculationformula of the first operator gate comprises a sigmoidal function. 39.The meta-application system of claim 38, wherein the sigmoidal functionis multivariate and substantially continuous, smooth, and monotonic. 40.The meta-application system of claim 37, wherein the confidencecalculation formula of the first operator gate includes a variable for aconfidence value associated with a bead received by one of the inputs ofthe first operator gate.
 41. The meta-application system of claim 1,further comprising a user interface that displays descriptions ofproblems detected by the analysis engine, as well as descriptions ofremedies associated with the problems.
 42. The meta-application systemof claim 1, wherein at least one of the operator gates comprises costestimates for acquiring missing inputs, the cost estimate of acquiringone input being distinct from the cost of acquiring another input,wherein the analysis engine is configured to acquire said one inputbefore acquiring said another input.
 43. The meta-application system ofclaim 1, wherein said at least one of the rules is an encodedrepresentation of a human-readable text document associated with thesoftware application.
 44. The meta-application system of claim 1,wherein said at least one of the rules further comprises one or morewires, each wire adapted to be used by the analysis engine to receive abead from one of the gates, each wire also adapted to be used by theanalysis engine to deliver a received bead to another one of the gates.45. A computer-implemented meta-application system for monitoring andanalyzing the operation of a deployment of a software application,comprising: a computer system comprising one or more computers, saidcomputer system programmed to implement at least: a monitoring componentthat collects data values of each of a plurality of state metricsassociated with the deployment of the software application; a repositorythat stores a plurality of rules, at least some of which map respectivelogical combinations of states associated with the state metrics tocorresponding problems; and an analysis engine that programmaticallydetects instances of said problems, at least in-part, by using the rulesto analyze the state metric data values collected by the monitoringcomponent; wherein at least one rule stored in the repository includesat least one query for a new data value for at least one of the statemetrics, and wherein the analysis engine is configured to initiate saidquery and use the data value obtained via said query in cooperation withthe rule to evaluate whether the problem associated with said at leastone rule exists within the deployment, the rules and the query beingrepresented substantially in a logic programming language; wherein therules collectively comprise logical formulae including predicates,logical operators, mathematical operators, free variables, and constantterms, the logical operators including AND and OR operators.
 46. Themeta-application system of claim 45, wherein the at least one rulecomprises an abstract remedy for treating the problem described by therule, the remedy comprising a set of one or more plans, each plancomprising steps and decision factors for correcting the problem, eachplan comprising at least one parameter, the system configured todetermine a binding for the parameter based on the data value obtainedvia said query.
 47. The meta-application system of claim 45, wherein theat least one rule comprises an abstract remedy for treating the problemdescribed by the rule, the remedy comprising a set of one or more plans,each plan comprising steps and decision factors for correcting theproblem, the system configured to customize a plan based on the dataobtained via said query.
 48. The meta-application system of claim 45,wherein each predicate represents a type of deployment state and has avalue of TRUE or FALSE, at least one of the rules comprising a logicalcombination of predicates joined by one or more of the logicaloperators.
 49. The meta-application system of claim 48, wherein eachpredicate comprises an open atomic formula representing a deploymentcondition, the open atomic formula comprising a predicate signature andone or more arguments, each argument of the open atomic formulacomprising a free variable or a constant term, the analysis engineconfigured to determine that predicates are TRUE by detectingpattern-matches between the open atomic formulae of the predicates andclosed atomic formulae indicative of specific deployment states, eachclosed atomic formula comprising a predicate signature and one or moreconstant term arguments.
 50. The meta-application system of claim 49,wherein each pattern-match between an open atomic formula and a closedatomic formula indicates that: a predicate signature of the closedatomic formula matches a predicate signature of the open atomic formula;a total number of arguments of the closed atomic formula matches a totalnumber of arguments of the open atomic formula; all of the constant termarguments of the closed atomic formula match corresponding constant termarguments of the open atomic formula; and a deployment componentassociated with at least one argument of the closed atomic formula meetsthe deployment condition represented by the open atomic formula.
 51. Themeta-application system of claim 50, wherein the analysis engine isconfigured to respond to a pattern-match between an open atomic formulaand a closed atomic formula by: binding at least one free variable ofthe open atomic formula with a corresponding constant term argument ofthe closed atomic formula; and evaluating whether a logical combinationof predicates of the rule containing the pattern-matched open atomicformula is satisfied when sufficient instances of the free variablewithin the predicates is bound to the constant term argument of theclosed atomic formula; wherein the meta-application is configured torespond to the analysis engine's evaluation that the logical combinationof predicates of the rule containing the pattern-matched open atomicformula is satisfied, by using the bound free variable to customize aremedy for solving a problem associated with the rule.
 52. Themeta-application system of claim 45, wherein the logical operatorsinclude at least one THEN operator that detects whether a timeassociated with a first condition is earlier than a time associated witha second condition.
 53. A computer-implemented meta-application systemfor monitoring and analyzing the operation of a deployment of a softwareapplication, comprising: a computer system comprising one or morecomputers, said computer system programmed to implement at least: amonitoring component that collects data values of each of a plurality ofstate metrics associated with the deployment of the softwareapplication; a repository that stores a plurality of rules, at leastsome of which map respective combinations of states associated with thestate metrics to corresponding problems; and an analysis engine thatprogrammatically detects instances of said problems, at least in-part,by using the rules to analyze the state metric data values collected bythe monitoring component; wherein at least one rule stored in therepository includes a plurality of gates each configured to be used bythe analysis engine to test for whether collected data values for one ormore of the state metrics indicate the existence of one of a pluralityof possible conditions of the deployment of the software application, atleast some of the gates configured to propagate temporal informationreflective of times that particular conditions were detected, theanalysis engine being configured to use the temporal information todetect a problem with the deployment.
 54. A computer-implementedmeta-application system for monitoring and analyzing the operation of adeployment of a software application, comprising: a computer systemcomprising one or more computers, said computer system programmed toimplement at least: a monitoring component that collects data values ofeach of a plurality of state metrics associated with the deployment ofthe software application; a repository that stores a plurality of rules,at least some of which map respective combinations of states associatedwith the state metrics to corresponding problems, the rules written in alogical programming language and collectively comprising logicalformulae including predicates, logical operators, mathematicaloperators, free variables, and constant terms, the logical operatorsincluding AND and OR operators; and an analysis engine thatprogrammatically detects instances of said problems, at least in-part,by using the rules to analyze the state metric data values collected bythe monitoring component, the analysis engine including a featuredetection component that analyzes a stream of data values of atime-varying state metric to detect a predefined type of feature of saidstream, at least some of the rules taking the feature into considerationin evaluating whether a corresponding problem exists; wherein thefeature detection component analyzes the stream, at least in part, byusing a mathematical model associated with the time-varying state metricto evaluate whether a behavior of the state metric includes the feature.55. The meta-application system of claim 54, wherein one of the rulescomprises an abstract remedy for treating the problem described by therule, the remedy comprising a set of one or more plans, each plancomprising steps and decision factors for correcting the problem, eachplan comprising at least one parameter, the system being configured todetermine a binding for the parameter based on a feature detected by thefeature detection component.
 56. The meta-application system of claim54, wherein one of the rules comprises an abstract remedy for treatingthe problem described by the rule, the remedy comprising a set of one ormore plans, each plan comprising steps and decision factors forcorrecting the problem, the system being configured to customize a planbased on a feature detected by the feature detection component.
 57. Themeta-application system of claim 54, wherein the mathematical modeldetects a feature comprising a rising or descending trend in thebehavior of the state metric.
 58. The meta-application system of claim54, wherein the feature detection component implements a seasonalityalgorithm to account for seasonal variations in the time-varying statemetric.
 59. The meta-application system of claim 54, wherein the featuredetection component applies a control chart algorithm to the stream todetect a deviation from mathematically modeled behavior of the statemetric.
 60. A computer-implemented meta-application system formonitoring and analyzing the operation of a deployment of a softwareapplication, comprising: a computer system comprising one or morecomputers, said computer system programmed to implement at least: amonitoring component that collects data values of each of a plurality ofstate metrics associated with the deployment of the softwareapplication; a repository that stores a plurality of rules, at leastsome of which map respective combinations of states associated with thestate metrics to corresponding problems, each rule expressed in a logicprogramming language; and an analysis engine that programmaticallydetects instances of said problems, at least in-part, by interpretingthe rules to analyze the state metric data values collected by themonitoring component; wherein the rules collectively comprise logicalformulae including predicates, logical operators, mathematicaloperators, free variables, and constant terms, the logical operatorsincluding AND and OR operators.
 61. The meta-application system of claim60, wherein the logic programming language is a substantiallyfirst-order logic programming language.
 62. The meta-application systemof claim 60, wherein at least one rule stored in the repository includesat least one query for a new data value for at least one of the statemetrics, and wherein the analysis engine is configured to initiate saidquery and use the data value obtained via said query in cooperation withthe rule to evaluate whether the problem associated with said at leastone rule exists within the deployment.
 63. A computer-implemented systemfor monitoring and analyzing the operation of a deployment of a softwareapplication, comprising: a monitoring component that collects datavalues of each of a plurality of state metrics associated with thedeployment of the software application; a repository that stores aplurality of rules, at least some of which map respective combinationsof states associated with the state metrics to corresponding problems;and an analysis engine that programmatically detects instances of saidproblems, at least in-part, by using the rules to analyze the statemetric data values collected by the monitoring component to detectfeatures of the deployment and convert the features into closed atomicformulas; and one or more computers configured to implement themonitoring component and analysis engine; wherein each rule correspondsto a potential problem with the deployment and comprises a logicalcombination of open atomic formulas containing free variables, theanalysis engine configured to match closed atomic formulas of detectedfeatures against open atomic formulas of the rule to produce outputvalue binding substitutions which logically combine to supplyinformation to a remedy for the problem, each substitution comprising anassignment of a value to a variable, the substitutions including one ormore variable assignments derived from closed atomic formulas ofdetected features.
 64. The system of claim 63, wherein the variables andthe features of the deployment are subject to unification to produce theoutput value binding substitutions.
 65. The system of claim 63, whereinthe analysis engine, in matching the closed formula with the openformula of free logical variables, is configured to produce a resultantformula representing at least a partial satisfaction of the openformula.